Seeing your “Studio” tag, it’s important to note that this will need to be used in Mendix Studio Pro, as far as I know this can’t be done in Studio YET
If you haven’t had a look at the Excel Importer module from the AppStore, I would recommend it: https://appstore.home.mendix.com/link/app/72/Mendix/Excel-importer
You can define Excel templates to help map your data to Mendix Entitry and Attributes. It is designed to be done through a UI but you can extend this module’s functionality to do it programmatically or “behind the scenes”
Hope this is what you’re looking for
if you are a java savvy, you can write a java action that does it for you. You will have full control, and manipulation, plus it is much leaner on the app.
I have done it and no issues so far, is been running for sometimes.