@KuroAnsatsu
He's level capped right now, so he won't level up, which is why he is training his skills to become stronger. We don't know what condition he needs to fulfill to break the cap and start leveling up again but I doubt these guys are it.
I guess he revealed himself because he wanted to actually confirm their intentions before hunting them down. Their behaviour was very suspicious but if you're going to kill someone, it might be best to clear any doubts about their nefarious intentions. I'm not sure he had any spare time to make a trap but getting a surprise kill definitely seemed in the books here. With that said, he's already shown that he can traverse forests very efficiently, when he was leading wolves on, and he's familiar with this particular forest. He's likely capable of running, hiding, and ambushing them one by one.
I wonder if it'd be weird of him to loot their bodies; they do have armor. I also wonder if this is something he'll report to the guards at the gates.
I'm looking forward to the next chapters as this is a really fun read.