Still... You'd not consider http://i271.photobucket.com/albums/jj125/Gizmojunk/data.jpg right?
Functionality falls second here IMO... though normally I would not want entire pages in decorative script...
I think a book's pages (in the game) should look indicative of the setting ~regardless of whether its harder to read the lettering.
UI font is obviously not the same used in in-game books, which is, are, much closer to what you seem to be asking for.
Does the font or the overall UI aesthetics break immersion for you?
For this specific font:
1) The condensed proportions are reminiscent of gothic type.
2) The slight embossed effect evokes metal type.
3) On the other hand, its distinctive enough to communicate the UI is a methaphor, not an in-game artifact like a book.
I mean the UI aesthetics, great, the functionality, not so much.
I mean things like taking me forever to go through all those potions, which are listed alphabetically, Lord know why, instead of by attribute they effect. THings like not being able to sort items through other criteria, etc.