Answer:
You can't have two tables in one model!
After creating a table you then create a model - this fails since the model already exists and as far as I can tell there is no SDO_RDF.add_to_model blah blah.

This may not even matter since all the models are stored in the same network and the tables store references to the RDF data that are loaded into the network.

So with better understanding: now the question is, one table/model for each RDF data file or throw everything together into one enormous table/model?? From the query examples I think I want to have all my data in one model as per

select x, y, name from
TABLE(SDO_RDF_MATCH(
‘(:Tom :hasParent ?y)
(?y :hasFather ?x)
(?x :name ?name)’,
SDO_RDF_Models(‘family'), ...);

Need to figure out if SDO_RDF_Models(‘family','order','plan') is possible???