If I read you question correctly, when you select a letter such as "F" a number of email addresses appear some of which you do not want to use. Simply put the arrow on the one you want and left click. The rest will disappear. You state some of them you want to "get rid of". I take that to mean you do not want to use them. Some email addresses may appear even though you do not have them in your address book. Just ignore them.