I am having exactly this problem with deleting a row from Excel using PowerApp.
My PowerApp uses both a SharePoint List and an Excel file stored in SharePoint. I create, update and delete the same data from both sources. I use the SharePoint List as my main source for the app, but add the Excel file so that I can download it and update a desktop version of the file (with macros) to refresh the desktop version. This way, I can use the app to provide an interface for viewing and modifying the data and use VBA to refresh that data for various users.
With "Assets" as the SharePoint List and "AssetsXL" as a table in Excel:
Remove(Assets,LookUp(Assets,Title=varTitle));
Remove(AssetsXL,LookUp(AssetsXL,Title=varTitle));
The SharePoint List remove the row as expected but the Excel Table does not.