Heat oven to 350ºF. Grease miniature muffin cups.
To make filling, in bowl, combine pepperoni, cheese, tomato, mayonnaise and pesto; mix well.
Cut each biscuit in half. Place biscuit halves in muffin cups, pressing gently to fit. Spoon 1 tablespoon filling into each cup.
Bake pepperoni bites 20 to 25 minutes. Serve warm.