There is a Export to Excel feature in the File Menu. This will export the data in the view to a spreadsheet.
Or you can save the form. (xml file) and then open it with Excel but this is not real clean and again it is just the data and not the layout of your view.
Those are your real options. Why do you need to convert to Excel? From a layout stand point you should be able to do everything in InfoPath you can do in Excel. Tables, etc.
You may want to look at the Database Accelerator. With it you can database all of your form data and aggregate it for reporting with Excel if that is what you need.
Qdabra Database Accelerator Suite Version 2.1 - Developer