The Settings - Export page will allow you to export your existing bookings to csv format, which you will be able to open in an excel spreadsheet or any other application that knows how to consume a file in csv format.

In order to export, you will need to use the export filters by selecting your service/availability and then providing a date or the customers email. Finally check the various pieces of data you want included in final result set for export along with the appointment status.

This will produce a file *.csv that is automatically downloaded by the browser.