that "exceptional blunt weapon" is probably a reference to real books like Les Misérables or War and Peace, which are around ~1200-1400 pages long and have versions that are up to 13cm (5") thick and weigh as much as 1-1.5kg (3.5lbs).
So the reincarnation served no point?
She could've easily just been an eccentric character in her own universe without the reincarnation.
I hope it serves some purpose in the future tho.
Without the reincarnation mind, the engagement would probably be broken off, or at least their relationship will not be as smooth as it is. Why? Because what makes the prince interested with her is her eccentricity based on previous life as avid fps/rts gamer. A normal eccentric person will need a big set up for any of them to like such thick book during childhood. Well, sure there might be children who loves difficult stories but it's as rare as blue moon. Even I would not want to read a book that thick if I don't have any interest in history.
...
Well, reincarnation can be seen as the easy way for the author to evade heavy backstory that is needed to develop a child to such eccentricity...
I'm not into FPS games myself, but I just love how inquisitive she is at the 'best places to snipe in the royal palace' so innocently with that gamer head of hers. I could get along with someone like her.