Match won - 1000xp
Match lost - 250xp
MVP - 800xp
Podium second - 400xp
Podium third - 200xp
Mastery Rank up - 2000xp
Mastery Challenge - 500xp

Elimination - 60xp - Any enemy player is eliminated
Revive - 80xp - Revive an ally
Survivor - 50xp - Don't die for the entire point
Survivor II - ?xp - Don't die for the entire round (all 3 points)
Survivor III - ?xp - Don't die for the entire match (6 points)
Marksman - 40xp - Capture a node and have it kill an enemy while it expands
Assistant - Assist an Elimination with your ability
Trickster - Escape laser elimination with your ability

Superior - 200xp - Have the highest elimination streak at the end of the match
Hero - 200xp - Have the highest revive streak at the end of the match

Class Specific
Ghost
Evader - Dodge an opponents attack with your ability

Theif
Devious - Marksman but for a stolen node

Blade
Trickshot - Kill an enemy with a dash coming from the other side of the wall

Smash
Trickshot - Kill an enemy with a dash coming from the other side of the wall

Snipe
Trickshot - Kill an enemy with a snipe within a short period of walking through a wall
Ranger - Kill a long distance enemy
Sharp - Kill an enemy quickly after deploying telemarker
Hair Trigger - Kill an enemy quickly after they crossed your line

Shock
Yay - Press Alt-f4.
Backlash - Kill an enemy after countering their ability

Thank you for reading this guide. Unfortunatly, i don't know how much XP all the things get you.
You can see when you get XP, because the game tells you in the top left corner of your screen.