A possible approach would be to bind to the excelImport event and convert the file to a JSON object, so that it can be assigned to a dataSource. You can dynamically add a new sheet to the component and use the setDataSource to bind the data. Here is a small example to demonstrate the suggestion. I would recommend a careful testing if using that or similar approach, as that is not a built-in feature.
Let me know how that works for you.