HEAT grill to medium heat.
COOK ravioli in large saucepan as directed on package, omitting salt. Meanwhile, brush zucchini and onions evenly with 2 Tbsp. oil; sprinkle with 2 Tbsp. cheese. Grill 5 min. on each side or until crisp-tender. Remove from grill; cut into 1-inch pieces.
DRAIN ravioli; set aside. Cook and stir garlic in remaining oil in same saucepan on medium heat 3 min. Add tomatoes; simmer on medium-low heat 5 min., stirring occasionally. Add ravioli; stir to evenly coat.
ADD grilled vegetables; mix lightly. Top with remaining cheese.