I have:
//todo: convertiere objekte in die Tabelle
ExcelEngine excelEngine = new ExcelEngine();
IApplication application = excelEngine.Excel;
application.DefaultVersion = ExcelVersion.Excel2013;
IWorkbook workbook = application.Workbooks.Create(1);
IWorksheet worksheet = workbook.Worksheets[0];
//Import the data to worksheet.
worksheet.ImportData(_excelObjekt, 2, 1, false);// "excelObjekt" contains a List<string[]>
workbook.SaveAs(filelocation);
workbook.Close();
excelEngine.Dispose();
But this will return a new empty excel file ...