Adding the Activities Feature Class and ActivityAssets Table to Map
Make sure to add the Activities feature class to the map before sharing it in ArcGIS Online or publishing as a REST service in the ArcGIS Enterprise Server. Add the ActivityAssets table to the same map as the Activities feature class.
Note the following:
Once the ActivityAssets table is added to the map, the relationship class is automatically established between them.
Make sure the contents of the map include only the feature class and not any base maps.