It means "Obviously a little kid"
It's used to insult pros and other players, or simply just to express your disrispect towards another person, mostly an opponent that plays unfairly.
Sometimes it can also be said simply as "olk" or "olks" which means: Obviously little kids..
It can also be used to approach your friends in a funny unserious manner.
Person 1: Hey, you oalk!
Person 2: Who? me?
4👍 1👎
Person 1: Hey! Can you lend me a helping hand?
Person 2: My anus is wide open for you..
Person 2: (making it much worse) Please come in, and take a seat.
2👍 1👎