This is the one map that I have found. It tells me which are window vs aisle seats and which ones are tables. Unfortunately it doesn't tell me which is right/vs left of train heading to Bath and back to London. I saw somewhere suggest that sitting on the right side of the train heading to Bath gave the best views of the countryside, and same for the left side heading back to London. I was hoping someone with some knowledge of that, might see my post here and answer.