Combine first 6 ingredients in large bowl and whisk to blend. Rinse ravioli under cold water to cool; drain. Add ravioli, ham, bell pepper, mushrooms and green onions to vinaigrette; toss to coat. Season salad to taste with salt and pepper. Cover and chill at least 30 minutes. (Can be prepared 3 hours ahead; mix occasionally. Let stand at room temperature 30 minutes before serving.)
Arrange salad on large platter. Garnish with olives, if desired. Serve, passing Parmesan cheese separately.