The minimum details I was looking for is more about how many crew/passengers can it serve for how long. My little bit of research looked at military ships and vacation cruise ships.
The largest ship in the Scouts I mentioned above is 1,000 dtons with a crew of 20 that only has one Galley on the ship. I prefer designing 1k dton ships and smaller, but I am a little interested in designing something up to 25k dtons in size sometimes, and I'm sure their crew/passenger sizes may require two or more Galleys, like a separate officers mess & enlisted crew/passenger mess..
The US Coast Guard buoy tender Bramble, which I inspected with the idea of purchasing it, had a galley of 15.5 feet by 15 feet, and could feed 80 men or so 3 meals a day on a 24 hour basis. Converting that into Traveller dTons comes out to 4.5 dTons, so round it up to 5 dTons. Then you have the galley used on long-range patrol planes by the U.S. Navy at the end of World War 2. You can find a downloadable description here on archive.org:
https://archive.org/details/FeedingInFlight
Based on the descriptions of equipment given in that, I would say that a galley adequate for 12 men, at a minimum, could be contained in One Traveller dTon of space. That should furnish adequate space for a grill top, oven below the grill, a microwave mounted about the grill, some refrigerated space, along with washing up facilities. You could replace the grill with a standard stove top if desired.
The U.S. Army assumes that 3.98 cubic feet of freezer and refrigerated space per man per month. One cubic meter converts into 35.314667 cubic feet, so each cubic meter of freezer and refrigerated space would be more than adequate for 8 men per month. (The actual figure is 8.79 men per month.) The Army Field Ration A, using both perishable and non-perishable foods, weighs 6 pounds per man, including packaging, and occupies 0.183 cubic feet of space. This would comprise both freezer, refrigerated, and shelf storage space. A cubic foot of combined space would hold food for 5 men for one day, with some space left over. You can do the math for whatever sized crew that you want.
If you go with non-perishable food, requiring no freezer or refrigerated space, equivalent to the Army Operational Ration B, when each ration weighs 6 pounds, included packaging, and occupies 0.1269 cubic feet of space. That means that one cubic foot of rations would weigh 42 pounds and supply food for 7 men per day. (The actual figure is 7.88.) Again, figure how much ration space you would need for your desired crew and for how long.
By ration, I mean that amount of food required to feed one man for one day. Now, the Army rations are figured on about a 4,000 calorie a day basis, so the food allowance for a ship's crew would be quite generous. For sedentary individuals and women, the food requirements should be less than the 4,000 calories.
For a rule-of-thumb calculation, one long ton, 2240 pounds, of rations will occupy 94 cubic feet of cargo space. Based on that, one Traveller dTon of space will hold 5 tons of rations. Assuming one man eating 6 pounds of rations per day, the man would eat 2190 pounds of food per year. Five tons of rations will feed 5 men for a year, assuming about 4000 calories per ration. Again, sedentary personnel are apt to eat less than 4000 calories per day, so that food allowance is quite generous.
All the data cited is taken from U.S. Army Field and Technical Manuals, which as a Quartermaster Officer, I would be using them for planning purposes.
