Hi Niko

Select all the sheets where you want to insert the row or column. You
can do this by clicking the sheet tabs where you want to make change
while holding down the Ctrl Key.

Now insert the row as you normally do. The row will get inserted in all
the selected sheets.
You can do this not only of inserting or deleting cell/rows/columns but
also to enter data, formats and host of other functions across various
sheets simultaneously.

Thanks
Karthik Bhat
Bangalore