A chopstick was a utensil used for eating on Earth.
T'Pol had trouble eating with chopsticks. On one occasion, Captain Jonathan Archer told Commander Tucker about T'Pol's "latest bout with chopsticks", to which Tucker complained that he had missed "dinner and a show". (ENT: "Silent Enemy")
Keiko O'Brien and her husband Miles ate their supper with chopsticks on the day Keiko told Miles that Deep Space 9 needed a school. (DS9: "A Man Alone")
Grand Nagus Zek, Quark, Krax, Rom, and Maihar'du used chopsticks to eat their tube grubs in 2369. (DS9: "The Nagus")
In 2375, the sixth Weyoun clone used chopsticks to eat aboard a runnabout after defecting to the Federation. (DS9: "Treachery, Faith and the Great River")