the common bowl on a table: a deep serving dish that several people at a meal reach into together
This is a plain piece of kitchen ware, a bowl deep enough to hold soup, sauce, or a thick paste, and wide enough for more than one hand at a time. It is not the drinking cup (ποτήριον) that went round at the same meal, and not a flat serving platter (πίναξ). Greek writers used the word for everything from a comic character's soup bowl to a measure in a doctor's recipe, which is a fair warning that its exact shape and size were never fixed.
Both New Testament uses fall inside a single scene. At his last meal Jesus says that the man who will hand him over is "the one who dipped his hand with me in the bowl." To modern ears that sounds like a private signal, but at a table like this everyone was dipping into the one bowl, and Judas can still ask a moment later whether Jesus means him. The words do not point out an individual. They name a relationship: the traitor is someone eating from the same dish, which is exactly the wound the psalm describes when a trusted friend who has shared bread turns on you.
The Greek Old Testament had already fixed the word's flavor. There it is the regular rendering of the Hebrew serving dish (קְעָרָה), and most often it names sacred tableware: the dishes that held the bread set out before God, and the heavy silver dish each tribal leader brought as an offering. So the word reaches the Gospels firmly attached to food and serving, with none of the sense of a cup or a chalice.
Disputed
What kind of vessel τρύβλιον actually named. The lexical tradition agrees it is a container for food but not on its form or size.
- majorityA bowl or deep dish: an open vessel wide enough for several diners to reach into and deep enough to hold a sauce or a dip.; LSJ, s.v. τρύβλιον; BDAG, s.v. τρύβλιον; J. P. Louw and E. A. Nida, Greek-English Lexicon of the New Testament Based on Semantic Domains, s.v. τρύβλιον
- minorityA technical word without etymology, naming a vessel of unknown form and varying size (it doubles as a unit of liquid measure in the medical writers), so no precise shape should be reconstructed from the word itself.; Hjalmar Frisk, Griechisches etymologisches Wörterbuch, s.v. τρύβλιον; Pierre Chantraine, Dictionnaire étymologique de la langue grecque, s.v. τρύβλιον
- minorityNearer a jug or pot than a shallow bowl or dish.; Henri van Effenterre, Revue de philologie 3e sér. 37: 41ff.