Another dishy readiness for kindergarten idea is 1 to 1 correspondence. While kids learn to say numbers when they are quite young actual counting comes later. They first have to understand that one number goes with one thing.
Setting the table is a meaningful activity to practice 1 to 1 correspondence. Each person needs 1 plate. With your child, name each person and put a plate out on the table or counter. Do the same thing with the forks and spoons. Does everybody get a knife or only the grownups?
When putting away the clean dishes, practice counting them. How many forks are there? And spoons? All this practice will help your child learn some valuable kindergarten readiness math, no matter how many people are coming to dinner.