The entity/detail dictionary table
SYS_ENTITYVIEWS record with name=Objv contains the following table views
Objv;Objv_User=User;Objv_Cont=Cont;Objv_Comp=Comp, this matches what you already detected.
You can extend this to other entities, but this will require some effort. Many other dictionary tables like
SYS_FIELDS, SYS_TABLES, SYS_RELATIONS needs to be extended in order to create the missing relation tables.
So, yes it's possible, but if you're knowledge of creating entities is limited to using the Entity creation wizard, be careful!