You can talk about what you think someone might be thinking with this phrase. For example:

You may be wondering why we changed it. Well, to be perfectly honest, it was a cost-cutting decision.

You may be wondering what this number over here means. That's the percentage of people in our survey that said that they only watch TV shows over the Internet.

People usually say "You may be wondering..." in speeches, essays, or other situations in which the audience can't speak back easily. In a one-on-one conversation with someone, you can ask a direct question:

Are you wondering how much it cost?