Cats love swatting at anything around them. That usually results in broken vases and ordinary items like eyeglasses, cups, and books being knocked off tables and thrown to the floor. In case you think your cat is just being a jerk (they are), the real reason might be because they’re just curious.
By swatting at things, cats learn what’s in their environment. It makes no difference whether they shatter a million dollar antique or just tip over your paper cup fill with a milkshake. Cats just like knocking things over to see what might happen because they can.