In Map Viewer, the ability to enable/disable editing is available in the Properties for feature layers that are editable.
It would be great to have the same option for tables as well - this is possible in Map Viewer Classic.
In my particular use-case, I have two tables in a map with a related feature layer, and need one to be editable and one to be read-only. I can do this through Map Viewer Classic for now, but it seems like it should be doable in Map Viewer too.