Uploading data to the application with a populated spreadsheet

I was wondering if there was a way to upload data from the application side. I was thinking it would be easier if there was a way to select a populated spreadsheet and then upload that from the application. Is that something that is possible?

Yes, you can definitely do that.

The easiest will be to get the users to upload a CSV file which you can then parse in the view JS.

Reference docs here