Being as ignorant as I am (was) about the period, Byatt's 'tell don't show' approach was what I needed! I doubt I'd have made as much sense of the novel without all the infodumps -- there were a lot, though I didn't find them overly intrusive.

Tom's feyness and Olive's 'close yr eyes and think of Faerie' mentality were part of what grabbed me -- Tom is as much his mother's creation as any of her (other) stories and if he wasn't so detached, directionless, indulged the betrayal wouldn't matter so much.