I fly between the U.S. and Europe several times a year, and I rarely experience any turbulence on those flights. The big commercial planes are very sturdy, and the turbulence is less apparent in those planes than the ones they use for domestic flights.
Last time I flew across the Atlantic, they warned us that there was turbulence ahead, but we never even felt it.
So don't worry. Enjoy your flight - and the free meals and drinks!
