Etiquette or social graces were the set of conventional rules of personal behavior on being polite that were expected and accepted as social norms.
Specifically, manners were ways of showing respect to others. More specifically, table manners were ways of showing good ways of eating at a table with utensils and with good behavior.
On 20th century Earth, Emily Post was considered a master of etiquette, a fact acknowledged by James T. Kirk after hosting a dinner for Klingon Chancellor Gorkon and his entourage in 2293. (Star Trek VI: The Undiscovered Country)
T'Pol suggested that Charles Tucker III's table manners during dinner could have offended the Kreetassans. (ENT: "Vox Sola")
In 2269, before James T. Kirk got into a sword-fight, a man said to him, "then you want better manners, free man. Defend yourself!" (TOS: "All Our Yesterdays")
Following William T. Riker, Deanna Troi, and Lwaxana Troi's abduction by DaiMon Tog in 2366, Lwaxana protested as Deanna and Will were Starfleet officers and the Ferengi ought to know better; Will quipped that "Tog must have missed that chapter in the Ferengi Book of Etiquette." (TNG: "Ménage à Troi")