To expand on Tim K's excellent tip (which I just found, sorry to necro the thread).
If you wish to create several book mark folders in one quick session, when you get to the step in Tim's tip above where you 'name the new folder' you click "OK" to accept the folder name, you now have two directions to take, tapping "Ok" then "Ok" again, moves your bookmark to the new folder. If you choose "Cancel" and "Cancel" you'll leave your bookmark where it was and return to the bookmarks view you were initially... tapping "Cancel*2" only cancelled moving the bookmark, the new folder was created and done with the first tap of "Ok" earlier.
Thanks again Tim!
HTH
-Dave