"Palatable" comes from "palate," a Latin-derived word for the roof of the mouth. The palate was once thought of as the seat of the sense of taste, so the word eventually came to mean "sense of taste," or broadly, "liking." "Palatable" has been used in English to refer to palate-pleasing foods since 1664, but it isn't our only — or our oldest — adjective for agreeable tastes. "Savory" dates from the 13th century. "Toothsome" has been around since 1551. "Tasty" was first used back in 1603. And "appetizing" has been gracing culinary reviews since 1653.
Of course, modern science shows that the tongue is the seat of the sense of taste, but even that has advanced since I was a child. Then it was believed there were four tastes: Sweet, sour, bitter, salty. And there was even a map of the tongue showing where each taste was felt. It wasn't until this century that Western scientists threw out the map (it turns out that most tastebuds can differentiate the various tastes), and accepted a fifth taste, umami, which occurs naturally in seaweed and mushrooms and is related to MSG, that was first identified by a Japanese scientist in the early 1900s.