A platter was a large plate used to display a selection of foods.
In 2270, several different kinds of fruit similar in appearance to those commonly found on Earth were served on a platter to Kirk, Spock, and McCoy while they were temporarily being held in the Lactra VII zoo. (TAS: "The Eye of the Beholder")
Also in 2270, platters on a dining table on the USS Enterprise held several different kinds of Earth fruit, as well as what appeared to be a selection of meats and vegetables. (TAS: "The Practical Joker")
In 2375, Neelix tried to bait B'Elanna Torres with the loaded statement "name your poison". She didn't take the bait, prompting him to exclaim disappointingly that he handed her the chance to give him a "scathing, but affectionate insult" to him "on a silver platter." (VOY: "Extreme Risk")
In an attempt to make Tom Paris jealous of his wife's ex-boyfriend Maxwell Burke, Harry Kim jokingly referred to Paris as "Turkey Platter", playing on the old nickname Burke had for Torres, which was based on the initials in her name, "BLT." (VOY: "Equinox")