You can use Model Reflection for that. Create an overview with the wanted data and add an 'export to excel' button and you're set.
Any soltuion would definetly rely on MXModelReflection to the data on entites, associations and attributes - https://appstore.home.mendix.com/link/app/69/Mendix/Mx-Model-reflection
as well as the Excel Exporter to get this data into an excel spreadsheet. - https://appstore.home.mendix.com/link/app/726/Mendix/Excel-exporter
Hope this helps,