I happen to be an English bookdealer based in Germany, but I find I don't know an English term (either a book trade term or something that people would understand).
I've got here a thing called ein Faltbuch or Leporello in German. It's a chain of 20 old postcards showing the delights of Karlsbad (now in the Czech Republic), and they're bound up as a linen hardcover. It's the sort of thing that, a hundred years ago, visitors to Karlsbad -a health spa- may well have bought as a souvenir. Someone must've bought this one in 1893.
Souvenir books like this were fairly common in some European countries, and there ought to be a word for them in English. Does anybody happen to know one?