Q: What did one plate say to the other?
A: Dinner is on me!
Explanation: When a meal such as breakfast, lunch, or dinner is served, it is typically put on a plate. If you go to a restaurant, the server may bring your food on a tray; the plates are then taken from the tray and set on your table. Your food is on the plate. So, if a plate full of food is talking, dinner (or lunch or breakfast) is really on the plate.
“Dinner is on me” is also an idiom that means, “I will pay for your food.” When you go to a restaurant and someone says to you, “Dinner is on me,” it means that the speaker will buy your meal. (Be sure to say, “Thank you” if someone buys your dinner!)
This joke is funny because it plays with the idiom, “dinner is on me.” Dinner is actually on the plate… and, in this joke, the plate will pay for dinner. (By the way, the title “My treat” is another idiom that means that the speaker will pay for the meal.)
Learn how to make a plate here: