Yes it is if you use Calibre to do it. Not on the device itself AFAIK.
To use Calibre please read:
and maybe: http://www.mobileread.com/forums/sho...d.php?t=192863
Those threads explain it all in sufficient detail.
I think the point about drag and drop is made in a post in one of these threads, the idea is to use a user column (for your Shelf column) that is (also) of type "Tag". Then the Tag will appear in Calibre on the left hand side pane and you can drag and drop on the Tag (shelf) you want thus easily multi-selecting and assigning books to a shelf.
The beauty is that you don't even need to resend the books to the device to (re)assign books to shelves.