waiting the tables
When a story takes a character who once had a lot to do and gives them some throwaway task to keep them busy. The term comes from the movie Ratatouille, when Linguini, who was once the restaurant’s top chef, is discovered to be faking it and Remi, the rat, takes over the kitchen, resorting Linguini to waiting the tables.
“Did you watch the new Star Wars movie? Finn was waiting the tables. He had nothing to do.”