I have downloaded wz_inventory mod but it only compress the items inventory. How to make the spell list smaller so that i can view more spells without scrolling?
Darnified UI is the exact solution. It decrease the font size in of all boxes, compresses the size of HUD, enlarges the map, make font and icon of inventory and spell list smaller.... See the two example images below Darnified UI+wz_inventory is also a good combination.
You should try the plugin "Clean Spellbook", it helps you managing your spells in a proper way. Spells are sorted by category, you can hide spells and restore them to be visible any time you want to!