Paste as values
In Excel, select all the data and copy it. Then paste it as values:
You can also get there by selecting the drop down under the Clipboard section of the Home ribbon:
You want to paste right over the top of the cells you're copying, essentially overwriting their content and converting your data from formulas to the result of the calculated formulas.
In other words, the cells currently might contain =1+1 and show 2 but by pasting as values, the content of the cell will actually be just 2.
Once you've done this, you can bring it into InDesign to work with and it won't go wonky on you.
By the way, this works in Google Sheets, too. You use the right click context menu and go to Paste Special > Paste Values or the dropdown menu Edit > Paste Special > Paste Values.