Group Worksheets with CTRL key
Hold down CTRL > Select tab and make changes to edit multiple worksheets at once.
This will group the worksheets together and whatever operation or task is performed on active worksheet will affect other worksheets in the group also. Best for formatting multiple worksheets at once if data is similarly structured. Or if you have chunk of data to be deleted from several worksheets at once.
Once done, ungroup worksheets by right-clicking on any worksheet > ungroup worksheet to deactivate.