a chamber: a room built into or alongside a larger building, almost always the temple
This is a plain architectural word for a room set within a bigger structure. It is not a freestanding house and not the main hall of worship: it is one of the side rooms, offices, lodgings, and storage spaces that ringed a major building. In the Bible that building is nearly always the temple, so the word becomes a kind of shorthand for the working rooms of the sanctuary complex, though it can also name a side room at a hilltop shrine or a room in the royal quarter.
The rooms differ only by who used them and for what. Some held the temple's wealth: the tithes of grain, wine, and oil, the sacred vessels, and the priests' stored portions. Some belonged to particular priests and Levites, who lodged, robed, and ate the holy offerings there. Some were the offices of royal scribes and officials whose work touched the temple. And in one early scene the word names a dining hall at a local shrine where a feast was served.
Because the room is defined by its place and its use rather than by any special form, the same word covers all of these. English translators reach for storeroom, chamber, hall, room, or office depending on the scene, but the underlying picture is constant: a built room serving the larger house it belongs to.