As far as I can see, the really major advantage of table cloths is they absorb a lot of noise, which bare wood does not. In a noisy restaurant this can make a huge difference, but may not matter in a smallish space with well behaved Cunard passengers. On the other hand, when I managed to knock over a nearly full bottle of Malbec in QG last summer, I imagine the staff would have been happier without table cloths to sort out.