When I attempt to import a spreadsheet when creating an application the operation fails with a quick message and I am navigated back to the file selection page. Is there a limit to the number of relationships, tabs, data that can be used to create an application from the spreadsheet
None other than physical limits to your laptop’s memory. Rather than the maximum limits, it is more likely that the contents of the uploaded file cause this behavior. Investigate the file, start with creating a copy of it with only the first couple of lines, and see if you can upload that one without problems.