Yes, you can. The information deletion is only happening on excel sheet will not have any affect on SDM.

Example: From SDM-> Get list of Incidents as below and click on Export (highlighted in below image).

Open the Exported excel sheet it shows red Indicators on Open date column. When we point mouse on indicator->comments are shown(highlighted in blue box of below image).

On excel sheet ->You can right click on column and select delete comment.

This will show changes only for this excel sheet. Next export of incidents from SDM will again show these Indicators and comments.

Or

On excel sheet -> select File menu-> Options->Advanced -> select radio button "No Comments or Indicators".

These changes are like permanent.In all exports of excel sheets from SDM-> you can no longer see any indicator and comments.

Once changes made from File menu are reverted-> you can again see the comments.