Hi Hannes,
I believe you'll want to do some pre-processing of this data before you upload it to AGOL, using a desktop application such as ArcGIS Pro or ArcMap. It sounds like your data as-is doesn't have polygons defined, and you'll need to get those from somewhere.
There are a few ways to do this and it'll depend what data and software you have access to, but I would recommend something like this in ArcGIS Pro:
- Find a geographic dataset containing the polygon boundaries you need from the internet. For example, for Swiss cantons, I'd check the Swiss federal government's open data site (I'm not really familiar with Swiss data sources) and look for shapefiles, File GDB feature classes, GeoJSON files, and so on.
- You'll need to perform a "join" (aka an "attribute join") between this geographic data and the non-spatial data you have in Excel. Here's some reference material on how to do this in ArcGIS Pro. One thing to keep in mind is that the names of each record have to be an exact match between the geographic dataset you're using and your Excel data, if the names deviate in any way (long form vs. short form, abbreviations, etc.) the join won't work as expected, in all likelihood some of your polygons will be missing. I would recommend making the join's output a File GDB feature class, in a new File GDB, but a shapefile would work as well.
- Open the new joined dataset to review the output, make sure it looks okay, and delete any fields you don't need.
- Zip the File GDB containing the joined dataset and upload it to AGOL, publishing it as a hosted feature layer.
It's also possible to perform joins without using a desktop tool - AGOL also has join tool - but since AGOL joins consume credits, I'd use a desktop tool instead.
