In the old GeoAnalytics you were able to use two inline tables as part of an GeoAnalytics operation, such as Within(), where both enclosed and enclosing could be inline tables.
However, in GeoOperations, this is not allowed:
"Only one inline table can be specified per operation. If you need to use data in two or more inline tables, you can use STORE to save the other inline tables as CSV files and then load from the CSV files."
I appreciate that there's a workaround, but this should really work like GeoAnalytics. Also, the GeoOperations GUI apparently does not know about this limitation and is happy to let you enter two loaded tables as inputs to Within(), even though it will fail when you try to load.