Literary: works that are valued for beauty of the words and the emotions they evoke.
Mainstream: a little more low-key than literary; enjoyable, but without the deep message sent by literary works. Used to be "general fiction", a catch-all for writings that don't quite fit in any single genre.
Experimental: missing commas, missing quotes around dialog, sentences that break off mid-page and continue three blank pages later.
Surrealism: hmm. don't know about that one, but it conjures up images of loads of dream sequences.
Have you tried googling the terms "surrealist fiction" and "experimental fiction"? The first two can be found at
www.agentquery.com/genre_descriptions.aspx
(note I did not quote them verbatim. Or at all, really.)