dunno about too many, my preference is for one bilingual, one monolingual and one pocket dictionary for each foreign language. it's somewhat obsolete in the google era and several of my en-pl dictionaries and reference books are older than I, but I'm too sentimental to toss 'em.

for me personally spacers would be pointless - I wouldn't stick to labels [barely care enough to put briefs and socks into their respective drawers], and other types of dividers would eat up valuable real estate. they might be handy for more organized people, though.