We all have those moments when we run out of things to say. ESPECIALLY when it is a woman we really like.
The most important thing is to keep the conversation going anyway you can. You have to avoid letting an awkward silence fall between you. She will most likely make an excuse to leave because she is feeling uncomfortable if you don't.
1) Anything to say, is better than nothing to say
2) Even if you go back to asking her about who she is, and what she does it is better than nothing
3) Use an opener (a line or routine that you use when you first approach a woman) or a story.
4) Move her to a different place (e.g. another part of the club or another cafe)
5) Drag out words, and talk slower (to give you time to gather your thoughts)