Best method to give two Oracle databases on the same server access to common data
You could store the catalogs tables in a separate schema on production.  test could then have a schema with the same name that uses views that select from the production tables using a database link.  This would make production fast because the data is local without requiring extra space.

If you decided that a particular table was too slow to access over the database link or having too great of an impact on production, then you could create a materialized view on test instead of a view.  You could create as many or as few of these as necessary to give the best balance of space and performance.

On the other hand, 1GB isn't that much space, so you might be better off importing into both databases even though it would double the space requirements.  It would have a speed advantage and would make test more like production.