Help with Data behind a map

[Malanto]

I am new to ArcGIS Pro and would like to understand the following:

Would it be possible to access the data behind each map that I visualize on ArcGIS Pro?

I am adding data from the maps portal but I cannot get the 'Attribute Table' for all maps I dowload. Is there a way to always get the data of a map in a table format?

[DanPatterson]

Not possible if there is no table.  Some raster data doesn't even have a table, but simply represents classed data.