The Excel macro has settings to limit how many rows and columns are rendered in the finished display. If a spreadsheet is rendered that has anything in a column or row it is rendered regardless of the limitations. Example:
A sheet is uploaded that has visible data in 15 columns and 60 rows with formulas to display data in the remaining rows up to row 500. The macro is configured to display 10 columns and 60 rows.
Once the page is saved all 15 columns and 500 rows are displayed; why?