33sec * 24fps * 1280px * 720px * 24bit/px
/ 8bit/byte / 1024 / 1024 / 1024 = ~2.1GB (not crazy at all, very logical )

Lossless is rendering every pixel exactly at it appears in an image for each frame. The only reason to render out from AE as lossless is if you're going to be doing further work with it.