Bring a pot of salted water to a boil. While water is heating, melt 1 tablespoon of butter in a large skillet over medium heat, and cook the garlic until fragrant but not brown, about 1 minute. Stir in the zucchini slices, and cook until tender and slightly browned, about 10 minutes. Season to taste with salt and pepper.
About 5 minutes after starting to cook the zucchini, stir the mushroom ravioli into the boiling water. Let them cook until they begin to float, about 5 minutes; scoop out the ravioli with a slotted spoon, and add them to the zucchini. Melt 1 more tablespoon of butter with the ravioli and zucchini, and drizzle the dish with truffle oil. Gently toss the ravioli and zucchini to thoroughly coat with butter and truffle oil, and serve.