this is quite easy. You need to use QueryBuilder to query the pages you are interested in. That is, read the page props. Then you can save the page props to a Java Collection and write the result set to an Excel doc that you create using the API.
This is all custom and can be implemented as an AEM Service.
Here is an older article that shows use of the Excel API within AEM (it reads from an Excel spreadsheet) -- Adobe Experience Manager Help | Creating a custom Excel Service for Adobe Experience Manager