To have enough on one’s plate

(Hint: this has nothing to do with food and an actual plate)

DEFINITION: Colloquialism meaning sufficiently busy or preoccupied with work, problems, or difficulties as to be unable or unwilling to cope with anything more.

EXAMPLES:

I have enough on my plate already!
I really wish I could help you with your psets this weekend, but I have enough on my plate as it is!

Oxford English Dictionary’s earliest example is from the July 4, 1928, issue of a British newspaper, The Daily Express:

Elton Pace: “I cannot say. I have a lot on my plate.”

Mr. Justice Horridge: “A lot on your plate! What do you mean?”

Elton Pace: “A lot of worry, my lord.”