What means 'ham' in baseball term?

Answer 1

There are a couple of answers for this.

According to the Dickson Baseball Dictionary, a "ham" by itself is just a ball player's hand.

ham-and-cheese is a pitch desired by the batter, usually a pitch right down the middle of the plate.

ham-and-eggs has two meanings. Dickson defines ham-and-eggs as an ordinary player or league.. or something not deemed as important, such as a relief pitcher who comes in to pitch for a winning pitcher in a blowout game.

Another well-known meaning for ham-and-eggs is a double play.