I'm afraid you overestimate how fast anything came become trendy in a slow universe like WOT, without publicity, literary milieu, fast means of travel etc. Works takes forever to become known and popular in such conditions,especially outside the big city in which they've been printed.

IRRC, Farstrider's book was his first, his second one was about travels with the SF. We know he also published a translation of the KC shortly before his disappearance.

As h0e disappeared over 20 years ago, "Travels" is probably decades old... which is why it's known and popular even with farmboys in isolated villages. Chances are a book like this would remain "trendy" for a few centuries, as is the case with the gleemen's tales.

It is Tam's favorite book, IRRC, and I think it's likely he bought it long ago while outside. It may be the only copy, or one of very few copies, in the TR area, if it's not reading this book as a youth which made him want to go see outside the TR. Tam probably bought it because he likes to reread it over and over. The way things were shown, it seems most people just borrow books they want to read from Bran al'Vere.

It's most unlikely there are many books in the TR that could reasonably be called "recent". Peddlers would typically carry only well established popular books.