The mess tables were stowed in the overhead between the deck beams. They were lowered into place for meal times. The "cook" would head for the cookshack with a bagged "duff" to be boiled [I believe it was once a week]. Each bag would have a numbered tag on it corresponding to the mess table. In addition, the person assigned as "cook" would be the one assigned to bring the mess kid from the galley to the table. Numerous descriptions of the process exist. I believe that O'Brian also includes a similar description.