All the stories contained in the books are quite ordinary in my opinion, they arn't drastic but... weird? The most controversial is that there are so many dead bodies in the desert. People in these stories dead in strange conditions, like stepping into their own fireplace or drunk found juice, at the sand of island... This isn't a seemingly scary place, but Desert is surely haunted.
My fave story is Diary of Morrin. It's little creepy about man who ate roll with ham :D
Here is good article about this https://www.reddit.com/r/TibiaMMO/comments/87062i/old_tibian_mysteries_jakundaf_desert/