I'm not sure what you mean by "staff." There are about 6,000 people on an aircraft carrier when the full airwing is embarked. A handfull of them are civilians

I'm not sure what you mean by "staff." There are about 6,000 people on an aircraft carrier when the full airwing is embarked. A handfull of them are civilians, but they usually fill senior administrative positions or provide technical expertise in support of maintenance; they're not there to perform menial tasks like loading vending machines. There are a relatively small number of enlisted personnel who specialize in "domestic" tasks: cooking, cleaning, etc. They are augmented by larger numbers of very junior enlisted personnel (E-3 and below) who are trained for other jobs but each serve a short stint working in service jobs. For example, a brand new seaman apprentice (E-2) electrician's mate finishes all of his training and reports to a carrier. For his first six months, he doesn't work as an electrician--instead, he gets sent to work in the ship's laundry; in the mess or wardroom; at the post office; cleaning and taking out trash; cutting hair; or serviung as a clerk in one of the convenience stores. When his time is up, he gets to go join his division and do the job he actually trained for. The job of restocknig the vending machines probably would reduce to about one or two people if that was all they did. In reality the job is spread out among quite a few more people, who also do other things. Typically it's the convenience store staff who do this.