I cannot speak for the A-330 specifically, but many airliners have side facing lights on the fuselage forward of the wing that actually shine slightly aft and illuminate either the wing leading edge or the engine nacelles and intakes (for aircraft with wing mounted engines) or both. This can help flight crew members determine if there is any buildup of ice on the wings or engine nacelles during night operations. However, in the U.S. generally these lights are illuminated during all takeoffs and landings when below 10,000' MSL, and also when crossing runways during taxi operations, both day and night, to enhance the visibility of the aircraft. On the A319/A320 these lights are called "Wing lights."
On the DC-9 and MD
-80/MD-90 aircraft, there are actually three side facing lights on each side of the fuselage--two forward of the wing and one aft of the wing. Starting from the front of the aircraft, the first light shines slightly aft and is used to illuminate the wing leading edge. It is called the "Wing Leading Edge Floodlight." The second light actually shines slightly forward and is called "Ground Floodlight" used to illuminate the ramp area near the forward cargo doors, and the aft light behind the wing is called the "Engine Nacelle Floodlight," and illuminates both the engine nacelle and the ramp area aft of the wing near the aft cargo door. On the DC9-50 aircraft, there is actually an additional light on the side of the fuselage (a fourth light) aft of the wing that is activated only when the emergency power is in use and will provide limited lighting for fifteen minutes during a ground evacuation using the overwing exits.
I hope this is what you were looking for.