They take the book when they leave, but the blank pages start to spontaneously fill with new grisly tales that come true.
Part anthology campfire tales movie, part straightforward ghost story where the protagonists try to right a historical wrong and lift a curse this is very much aimed at older kids in a "my first horror movie" kind of way.
None of the scary stories are overly original and most are sort of subverted by the protagonists knowing what's going to happen (from reading the book) and trying to prevent it. They do however throw nice makeup and visual effects at them.
Oddly there's a lot of inclusion of period detail, especially relating to the election of Richard Nixon and Vietnam War. We get the revelation that Ramone, the stranger with the car, is passing through town because he's a draft dodger but that's a big pile of irrelevant meh. It's part of an attempt to be very meta about "writing you own story" but it falls utterly flat.
This all results in a very uneven movie. If you've got kids you want to introduce to horror movies this will probably serve very well, its pitched nicely for that I think.
For anybody else it's neither one thing or another. It's not camp enough to be funny, not meta enough to be watched for references and not scary enough to just be a horror movie. You've got better things to do with your time 5/10.