Yes it is possible. If you want a more advaced spellbook that you can have passive abilitis and such I recomend:
http://www.wc3sear.ch/index.php?p=Spells&ID=836&sid=
(Vexorian you is my hero)
Else you can to it this way:
Learn ability
Events
Unit - A unit Learns a skill
Conditions
(Learned Hero Skill) Equal to <your ability>
(Level of <your ability> for (Learning Hero)) Equal to 1
Actions
Unit - Remove <your ability> from (Learning Hero)
Unit - Add <your ability as spellbook> to (Learning Hero)
Player - Disable <your ability as spellbook> for (Owner of (Learning Hero))
<your ability> is a normal ability.
<your ability as spell book> is a spellbook only containing <your ability>.
Hero abilities can not be added to a spell book but It is an work around:
Make the ability a Unit ability, add it to the spellbook then make the ability you made to a hero ability. And voila you have a spellbook with a hero ability inside.
For this to work your hero must have a spell book from the begining.
Actually i dont come up with this myself. It was Vexorian's spellbook exeriment. But I dint need all things in his experimetn ad I removed it all and ceeped this. To fix a bug i added the last line in the trigger. (the bug was not caused by Vexorian but by my removing of his JASS code in the exeriment)
-edit-
Of i seems that passiv abilities can be in a normal no jass using spellbook since patch 1.18. That seems do undo all of Vexorians hard work or have your exeriment more advanced fetures?) (no need to answer)