"Hello and I am alive"
The phrase is a bit odd, but it's a humorous way of saying "hello" with a playful implication of being alive and well.
Here's the breakdown:
* Hej: Hello (similar to "Hi")
* a: and
* je: you are
* gjall: alive
It's not something you'd typically hear in everyday conversation, but it's used in specific situations to express humor or add a lighthearted touch.