Need a Brunch spot with Private Room for 50 in Lower East Side, Chinatown, Soho or The Village
I would vote for Chinatown Brasserie myself. You could also try Woo Lae Oak -- they have a couple different private rooms (might be a stretch to call it Brunch but you could do Lunch). Went to a friend's bridal shower at Rosa Mexicano and they also have a private room that should work for you.
9 E. 18th St., New York, NY 10003
Woo Lae Oak
148 Mercer Street, New York, NY 10012
380 Lafayette St, New York, NY 10012