For additional meanings of "Plate", please see Plate.
"This is a plate. It contains food."
– James T. Kirk to Elaan, 2268 ("Elaan of Troyius")
Several plates in 2151
A plate was a flat dish, similar to a platter, on which food was placed.
Plates were in use in the mess hall and captain's mess aboard Enterprise NX-01. (ENT: "Terra Nova", "The Andorian Incident", "Breaking the Ice", "Fortunate Son")
The plates pictured above, used in "Terra Nova", were later sold at the 40 Years of Star Trek: The Collection at Christie's. [1](X) [2](X)
In 2268, James T. Kirk suggested he could teach Elaan table manners, beginning with the function of a plate. (TOS: "Elaan of Troyius")
In 2269, Montgomery Scott suggested to a frustrated Leonard McCoy that a tardy James T. Kirk, Spock, and the supposed Abraham Lincoln were in the galley "looking up a plate of haggis." (TOS: "The Savage Curtain")