I thought we were only able to get one item, plus the gold. Or is there a chance to get more than one item when we turn in the tasks? Also, I have no idea what the 4th reward that I earned is. I do not keep track of the number of each item I carry, so its not like I will be able to go through all of my items and figure out which item it was.

Yep. Tasks can award up to 3 salvaged materials. However, Tier 1 Weekly Tasks have no valid 3rd reward atm and it was trying to trigger and award it - but nothing was there to reward. I added a check now so it won't award a nothing anymore.