Blazor code below. BlazorDownloadFile is a Javascript function on this page that handles the download of the workbook created in Blazor.

        
@using System.IO
@using OfficeOpenXml
@using Microsoft.JSInterop
@using System.Net
@using System.Reflection
@using System.Dynamic
@using System.Text.Json
@using OfficeOpenXml.Table
@inject IJSRuntime JS

@code {
    async Task DownloadExcel()
    {   
        using(var package = new ExcelPackage())
        {
            // Add a named style for hyperlinks
            var ns = package.Workbook.Styles.CreateNamedStyle("Hyperlink");
            ns.BuildInId = 8; //Build in type 8 is Hyperlink
            ns.Style.Font.Color.SetColor(eThemeSchemeColor.Hyperlink);
            ns.Style.Font.UnderLine = true;

            var sheet = package.Workbook.Worksheets.Add("Cities");

            await LoadCitiesListFromJavascript(sheet);

            // add a hyperlink to next worksheet
            var nextWorksheetHyperlink = new ExcelHyperLink("'Fx Rates'!A1", "Go to next worksheet");
            sheet.Cells["A13"].Hyperlink = nextWorksheetHyperlink;
            sheet.Cells["A13"].StyleName = "Hyperlink";

            // Adjust the column width after the widest text in the cells
            sheet.Cells[1, 1, sheet.Dimension.End.Row, sheet.Dimension.End.Column].AutoFitColumns();

            // read png image from embedded resource
            using var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("EPPlus9.WebSampleMvc.NetCore.WebAssemblySamples.Resources.EPPlus-logo-full.png");
            var pic = sheet.Drawings.AddPicture("epplogo", stream, OfficeOpenXml.Drawing.ePictureType.Png);
            pic.SetSize(50);
            pic.SetPosition(0, 10, 0, 10);


            // call an api endpoint to retrieve json data with fx rates. 
            var client = new HttpClient();
            var url = new Uri(new Uri(_navigationManager.BaseUri), "/api/fxrates");
            var response = await client.GetAsync(url);
            var fxRatesJson = await response.Content.ReadFromJsonAsync();
            var fxRates = JsonSerializer.Deserialize>(fxRatesJson);
            CreateTableAndChartWorksheet(package, fxRates);

            // finally serialize the workbook to a byte array and use the BlazorDownloadFile function to create a link for download.
            await JS.InvokeVoidAsync("BlazorDownloadFile", "BlazorSample1.xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", package.GetAsByteArray());

        }
    }

    private async Task LoadCitiesListFromJavascript(ExcelWorksheet sheet)
    {
        // get some json data from a javascript function and convert it into ExpandoObjects (dynamic objects)
        var json = await JS.InvokeAsync<string>("getCities");
        var cities = JsonSerializer.Deserialize<IEnumerable<ExpandoObject>>(json);
        // load the dynamic objects into EPPlus using the LoadFromDictionaries method.
        var loadedRange = sheet.Cells["A5"].LoadFromDictionaries(cities, x => {
            x.TableStyle = OfficeOpenXml.Table.TableStyles.Medium13;
            x.PrintHeaders = true;
            x.DataTypes = new eDataTypes[] { eDataTypes.String, eDataTypes.Number, eDataTypes.String, eDataTypes.Number };
        });
        var table = sheet.Tables.GetFromRange(loadedRange);
        table.ShowTotal = true;
        table.Columns[0].TotalsRowLabel = "Average";
        table.Columns[1].TotalsRowFunction = RowFunctions.Average;
        table.Columns[3].TotalsRowFunction = RowFunctions.Average;
        sheet.Cells[table.Range.Start.Row, 2, table.Range.End.Row, 2].Style.Numberformat.Format = "#,##0";
        sheet.Cells[table.Range.Start.Row, 4, table.Range.End.Row, 4].Style.Numberformat.Format = "#,##0 \"km2\"";
        // Calculate the formulas in the worksheet, in this case the average functions of the table's total row
        sheet.Calculate();
    }

    private static void CreateTableAndChartWorksheet(ExcelPackage p,IEnumerable? data)
    {
        var ws = p.Workbook.Worksheets.Add("FX Rates");
        ws.View.ShowGridLines = false;

        var range = ws.Cells["A20"].LoadFromDictionaries(data, x =>
        {
            x.TableStyle = null;
            x.DataTypes = new[] { eDataTypes.DateTime, eDataTypes.Number, eDataTypes.Number, eDataTypes.Number, eDataTypes.Number, eDataTypes.Number };
            x.PrintHeaders = true;
            x.Culture = CultureInfo.InvariantCulture;
        });

        ws.Cells["A:A"].Style.Numberformat.Format = "yyyy-MM-dd";
        ws.Cells["B:F"].Style.Numberformat.Format = "#,##0.00";

        ws.Cells[22, 7, range.End.Row, 11].Formula = "B$21/B22-1";
        ws.Cells["G:K"].Style.Numberformat.Format = "0.00%";

        ws.Cells["B20"].Value = "USD/SEK";
        ws.Cells["C20"].Value = "USD/EUR";
        ws.Cells["D20"].Value = "USD/INR";
        ws.Cells["E20"].Value = "USD/CNY";
        ws.Cells["F20"].Value = "USD/DKK";

        ws.Cells["G20"].Value = "USD/SEK %";
        ws.Cells["H20"].Value = "USD/EUR %";
        ws.Cells["I20"].Value = "USD/INR %";
        ws.Cells["J20"].Value = "USD/CNY %";
        ws.Cells["K20"].Value = "USD/DKK %";

        //Add a table over the range including the . 
        var tbl = ws.Tables.Add(ws.Cells[20, 1, range.End.Row, 11], "Table2");
        tbl.TableStyle = OfficeOpenXml.Table.TableStyles.Dark6;

        ws.View.FreezePanes(21, 1);

        CreateLineChart(ws, range);

        ws.Calculate();
        ws.Cells.AutoFitColumns();
    }

    private static void CreateLineChart(ExcelWorksheet ws, ExcelRangeBase range)
    {
        var chart = ws.Drawings.AddLineChart("LineChart1", eLineChartType.Line);
        var s1 = chart.Series.Add(ws.Cells[21, 7, range.End.Row, 7], ws.Cells[21, 1, range.End.Row, 1]);
        s1.HeaderAddress = ws.Cells["G20"];

        var s2 = chart.Series.Add(ws.Cells[21, 8, range.End.Row, 8], ws.Cells[21, 1, range.End.Row, 1]);
        s2.HeaderAddress = ws.Cells["H20"];

        var s3 = chart.Series.Add(ws.Cells[21, 9, range.End.Row, 9], ws.Cells[21, 1, range.End.Row, 1]);
        s3.HeaderAddress = ws.Cells["I20"];

        var s4 = chart.Series.Add(ws.Cells[21, 10, range.End.Row, 10], ws.Cells[21, 1, range.End.Row, 1]);
        s4.HeaderAddress = ws.Cells["J20"];

        var s5 = chart.Series.Add(ws.Cells[21, 11, range.End.Row, 11], ws.Cells[21, 1, range.End.Row, 1]);
        s5.HeaderAddress = ws.Cells["K20"];

        chart.XAxis.Crosses = eCrosses.Min;

        chart.To.Row = 19;
        chart.To.Column = 11;
        chart.Legend.Add();
        chart.Legend.Position = eLegendPosition.Bottom;
        chart.StyleManager.SetChartStyle(ePresetChartStyleMultiSeries.LineChartStyle9);
    }
}