We asked to be moved in one of the PG restaurants on QE2 because we were at the edge of the "smoking section" (no divider, just an imaginary boundary). Several heavy smokers made it a miserable dinner. One couple smoked constantly. I don't know how they managed to get in a meal, too.
And to go back to the banquette discussion, didn't one of the PG restaurants on QEs have a row of banquettes? I have a vague memory of that being the smoking area.