You can already use the right click menu to copy a range of cells.
I'd like to point out a couple of other important Copy' and 'Paste' options'.
Right click on the top left cell of the range you want to copy.
Right click on the top left cell of where you want to paste it.
You then see a context sensitive row of 'Paste Options'.
You only see the options that are available:
Select the one you want and left click.