go to gameserver/config/character and search for
# This will control the inventory space limit (NOT WEIGHT LIMIT).
# Default: 80, 100, 250
MaximumSlotsForNoDwarf = 80
MaximumSlotsForDwarf = 100
MaximumSlotsForGMPlayer = 500
MaximumSlotsForQuestItems = 100
and change to how many u need :)