It was Shakespeare who said, "If music be the food of love, play on." The full context of the quote was:
"If music be the food of love, play on,Give me excess of it; that surfeiting,The appetite may sicken, and so die."
This quote comes from Act One, Scene One, lines one through three from the play Twelfth Night.
Shakespeare coined a great deal of quotations that are in common usage today. The words here are not too complicated too unpack.
Page through some of Shakespeare's other works. You will quickly find that he frequently uses images of food to demonstrate love and a whole field of other emotions and ideas.