Oolong (the pig), Yamcha (another pig) and Puerh are all types of tea !.

Gohan, Vegeta(ble), Raditz (radish), Nappa (cabbage), Bro(co)ly and all of the saiyans are named after food. Goku's real name is Kakarot. His father is Bardock, etc.

Cooler and Frieza are obvious, they get to be where food gets to die after being forgotten.

Ten Shin Han is a dish with crab (or shrimp, I don't remember)

Piccolo is named after an instrument, so were the other demons (Drum, etc.)

Bulma comes from Bloomers, a type of female underwear. Trunks are the male equivalent.

Bididi Babidi Boo ! Is the formula used by the good godmother (or whatever her name may be) in Cinderella.

I think I must have forgotten some characters, but you get the gist of it.