Experienced party planners keep extra hors d’oeuvres in the freezer for such moments.
If that’s not an option, have someone slip out to the nearest supermarket. Most stock trays of prepared vegetables, dips, cheeses, and cold cuts.
If they don’t, here is a shopping list for a dozen hungry grazers:
500 grams sliced Genoa salami
500 grams sliced smoked ham or turkey
1 kilogram Swiss or American cheese
1 jar spicy mustard
2 boxes crackers
2 loaves French bread or baguettes
1 jar green olives
1 large bag bite-size peeled carrots
2 small baskets cherry or grape tomatoes
1 large bunch grapes
500 grams dried apricots