Product:
Cognos TM1 10.2.2
Microsoft Windows 2012 R2 Server
Microsoft Excel 2010

Problem:
The Web sheet becomes too wide on the TM1WEB so you need to scroll to the right.
You have marked the columns in the Excel workbook sheet and select delete columns.
But it has not helped.
If you press CTRL+END you still end up all the way to RV column.

Solution:
Mark the columns on the right side that you do not want to see.
Then select HIDE from the right-click menu.

Save the excel sheet.
Update the excel sheet to TM1WEB, with Perspective toolbar.