This belonged to my grandfather. I only know that he served in Africa near the end of the second world war and "ran a supply ship" as my dad put it. He didn't talk much about the time he served to his kids and he passed away while I was fairly young. I haven't studied much of WW2 aside for standard highschool classed, so please excuse me if I seem ignorant of certain facts.
That is a Hitler Youth Knife. Each member of the Hitler Youth had one, it was used as a tool, sort of like a Boy Scouts camping knife would be used.
The mark on the blade is the manufacturers symbol, an RZM 13 signifies this knife was made by Arthur Schuttelhofer & Co., Solingen-Wald