Uploading file, parsing and displaying data
I would create a new url where files can be uploaded. This is done with a implementation of hook_menu.

If you want to use Feeds you first need to upload the file and have it converted to rss/csv/opml etc and then use Feeds to map against a node. I would go with a custom module instead so that you can create nodes straight away instead of a "two step operation".

You can find out how to create a form that handles file uploads here. In the submit function for your form you would need to programatically create nodes from the file upload. This can be done in several ways but one is by using Entity metadata wrappers, which I find easy to work with. You can find out more about that here.

This all might sound like a lot of work and I didn't suggest a contributed module but I think in your case it would be more work to first convert the data to something readable by Feeds for example.