It might be some kind of written or verbal task and you have to explain how you handle some kind of class room situation, though I think it's more likely to occur in the interview. I had a 'test' at the beginning of an interview once and I had to outline a lesson plan for a set group of learners, transcribe words into the phonetic script, outline the areas I wanted to develop etc.

Or you might just have to teach a class! Hehe.

Good luck!

Let us know what the task is!