Twice the CEO of our company sat next to me (also across from me) during lunch in the company. He asked some general informal questions which I answered but didn't ask him anything in return. I want to know whether I should ask him questions or not.
If yes what can/should I ask? Or how shall I converse with him during the lunch when he is sitting next to me (or across from me)?
Additional Info: Company is 14 years old, much like a start up although not exact.
Note: I didn't ask this question on workplace as I think it is more of an interpersonal skill owing to be an informal serendipitous or coincidence of having lunch with the CEO rather than a pre-planned formal lunch having professional elements.