Will my charts be compromised if I use Excel file with charts and multiple related sheets?

No, they won't. Actually we are using exactly the same Excel file you upload. We are not importing your data in any other database. We are using your original file.

If you have relations between two Excel sheets or a chart extracted from any data in your Excel file, they will remain untouched. This means that you can update your Excel file online, and after some period of time you can download the populated file and still have your charts and formulas working properly. Please note that formulas and charts update only after the workbook is opened in Excel.