What does this circled number means in Movies and TV beta?
That is your Reputation score on Movies and TV. I think From the screenshot, that is your monthly score, i.e. the reputation you have accrued in May.
Reputation is a (or even the) core concept on Stackexchange, you earn it by being recognized for your contributions by other users and you gain privileges from it. Look at the link above and read about it in the FAQ.