Mai gives the tomes a quick once-over, reading just enough to get a sense for what they are before stopping and returning them to where they'd been safely stored, taking extra care that they wouldn't be damaged on the trip back.
"These books are ancient. Very ancient, maybe the oldest in existence. I've no doubt they tell of some very interesting things about the place we just were, but I'd rather not risk damaging them. Perhaps back in Waterdeep there will be some means of preserving them."