Preheat oven to 400°F (200°C).
In a large bowl, combine all meatball ingredients: ground beef, bread crumbs, onion, milk, parsley, salt, Worcestershire sauce, pepper, and eggs. Mix gently until just combined.
Shape mixture into 1 inch meatballs (about 1 tbsp each). Place in an ungreased 13x9 inch pan or on a rack in a broiler pan.
Bake for 18-22 minutes, or until no longer pink in the center.
While meatballs bake, make the sauce. In a large Dutch oven or pot, combine chili sauce and grape jelly. Heat over medium, stirring constantly, until jelly is melted and smooth.
Using a slotted spoon, transfer the baked meatballs into the sauce. Stir gently to coat.
Simmer uncovered over low heat for 30 minutes, stirring occasionally.
Serve hot with toothpicks.