It will show you all the data entities which are available in the system based on customer (CustTable) as the main data source. Select the first one,
and it will open an excel sheet with Dynamics Add-ins. You might need to sign in using a valid user which have access to D365Fo application. Excel must look like below with a Dynamics add-ins in left.
You can perform all CRUD operation here and hit publish button on the left down side to publish your changes to the server. That’s it.
Now coming to the title of this post, (it's not too late ) if you want to make any changes on these fields, like remove and add new or want to change the order, here is the trick.
Go to visual studio, open the data entity (in this case you need to create an extension of this entity). Go to field group > AutoReport. Here you must get all field which is showing on excel. You can do addition, delete, change the order of fields and that’s it. Once successful build changes will reflect when you use excel add-ins next time.
Cheers,
Harry