The general goal of using WordBanker is to remove as many words as possible whilst being certain that you are sure of the word before you remove it. Removing words is best done during testing by clicking the 
in the test window.
Whenever you remove words whilst testing or from the set manager it is send to a "removed words" set (similar to a recycle bin) and can be retrieved later if you have forgotten it. If however you want to remove all the words in a set you may not want to send them to the "removed words" set which is why you are given the option just before doing so.
