Guild Wars 2

Hi,
I recently created new character, i’m on 5 lvl, when creating iron slab i’ve noticed that only evry tenth or so item adds experience, nonetheless after each item experience number pops up in the middle screen but not adds to the overal number

That’s not a bug. You get ‘crafting experience’ that moves the bar at the top of the crafting window. When you gain a crafting level (like, going from 100 to 101 armorsmithing or whatever) you gain character experience. The numbers you see popping up for each craft is the crafting experience.