Table function?

I've been trying to find the description of the sql TABLE function.  But, the word is so common that I haven't been able to find what I'm looking for.  Please see the select statement below.  The "FROM TABLE(..." clause is my interest.  Can someone point me to the documentation that describes the table function?  It seems like it would have a lot of uses.

SELECT PLAN_TABLE_OUTPUT

  FROM TABLE(DBMS_XPLAN.DISPLAY('MY_PLAN_TABLE', 'st1','TYPICAL'));

Thank You