You can do that right now with a little tweaking of the provided webform. What type of file can be uploaded is just restricted by the upload elements each webform provides, means you can really upload anything.
Go to structure/ webforms/ and press on the descriptive metadata webform. You will get - lot of tabs, press on Buid. You will see a list of elements, the following step will depend on your needs. Just to try this out select one of the file upload elements (there is one for documents). You will get now a new settings form to the right of your screen where you can set the allowed file extensions. Add csv, docx, etc using space separated list as explained there. Save and test editing or ingesting an object. Remember that certain webform elements show up/are hidden based on users decisions (like media type). You can also change/tune that on the same upload element settings form on one of the tabs.
Happy to go into zoom mode to guide you through this or even organize a ingest workflow workshop in the few next days
Let me known if this helps
Once uploaded, showing the csv/searching inside eequires some beta3 code we are preparing but allowing people to download it is just a change in one of your metadata displays(twig template) can share a drop in replacement if you want
Cheers
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Diego Pino NavarroDigital Repositories DeveloperMetropolitan New York Library Council (METRO)