The objective is to give to each adventurer a quest matching their stats to maximize their probability of success, so for example if a quest requires at least 5 perception (symbolized by the eye) and 2 luck (symbolized by the clover), then you will give it to a hero that has at least these stats. The filling circle around each stat represent the level of the stat
I made it so you don't really have to know exactly which stat correspond to what, you just have to be sure that the hero stat is higher than the stat on the parchment (the stat request of a quest)
but if you really want to know :
The blade represent strenght
The clover represents luck
The bulb represents intelligence
The medal represents bravery
The feather represents agility
The lightning represents Endurance
The eye represents perception
The shield represents resitance