I’ve seen this question in similar forms especially regarding how much a cargo hold itself can carry.
In an effort to simplify some stuff, I came up with using some other modules as reference points. For instance, I average a ship torpedo to be about 1m diameter and maybe 3.5m long (4’x10’ approx). It works for me but you can go with whatever sounds good. The point is, I then looked at stasis module since my spare torpedoes will be packaged similarly (rows and shelves), taking into account extra packaging and special equipment. I estimate then that each torpedo is about the same width as a bed, and maybe 1.25 to 1.5 the length, so guess for 1 bed wide 2 beds long. A class 4 stasis module can hold 64 beds, and torps take 2 spaces. 32 torps in storage. Add up equipment to move them around (trolleys, cranes, whatever) and enough space to get at what you need and there you go. A class 5 could hold 128 and a class 2 is carrying 2 extra, per hold. You could have the torps shorter and then match the storage to stasis, or make them even larger and reduce even more how many you can carry.
As far as moving them around the ship, I would rule it depends how far you have to go. Each module takes time to traverse and off the cuff I’d say 1 round per room, modified by the number of successes from a dexterity test (don’t want to knock a stack of them over halfway there, heh). As well, I’d rule a designed trolley could handle 4 (a full reload) at a time.
If you give it a go, or find a different idea, I’d like to see what else comes up J
Oh, and given you’re packing dozens of torpedoes in one room, a hit really should be eye opening for the players.. Might want to reinforce that room and surround it with other modules lol)