I believe that is client side.. Can't really turn off the book. If you plan on modding your client, you can delete the book gump from the paper doll.
 
Where do i enable /disable the weapon abilities book?
I have a kind of fix for you, the book will still be there but the players wont be able to use the abilities.

in Scripts/Abilities/WeaponAbility.cs at line 274, create a condition that players could not complete
-example-

if (from.Title != ( ",RANDOM" ))
{
from.SendLocalizedMessage(1063456); // You must upgrade to Samurai Empire in order to use that ability.
return false;
}

only a player with title "RANDOM" would be able to use abilities, others will get the message to upgrade to samurai empire. You can also edit the message to say something like these are disabled or so.
 
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