And in "Tomorrow is Yesterday," why did the transporter room have a food slot in the wall?
If the ship has one set of machines to prepare food, and another set to fabricate parts and supplies, then all of these various products could be delivered to their ultimate destinations using the same turbo-dumbwaiter system. If they're not too large. The "food slots" in the transporter room's primary
purpose could be high speed delivery of small repair components to the transporter operator.