HI Nguyen,
Thank you very much for using Syncfusion products.
We have tried the sample at our side to Export the sheet data to the data table and we could not reproduce the reported issue. We have attached the sample for your reference.
In the sample, the input file "NorthwindDataTemplate-Copy.xls" the column D "Contact Title" does not contain the data and when exporting to the data table , the data table contains the Column Name and "Null" values in that column values.
If i remove the Column Name and data values in the Column 'D' the data table contains the Default Column name "Column1" and null values for that column.
Please try the sample at your side and let us know if these helps you.
Please let us know if you require any further clarifications.
Regards,
Sridhar.S
ImportExportDataTable_4f3b6b9.zip