Expression from the late 1960s until the early 1970s. Literally means "give it to me," but generally had a underlying sexual connotation. Could also mean just give me your best.
Goldie Hawn would say "Sock it to me, " on the TV show Rowan and Martin's Laugh-in, while wearing a flowered bikini. The Isely Brothers sang, "I can't tell you who to sock it to." A person could say, "I have an idea," and the response would be.."OK. Sock it to me."