Prior to Oracle 12C you cannot select from PL/SQL-defined tables, only from tables based on SQL types like this:
CREATE OR REPLACE TYPE exch_row AS OBJECT(
currency_cd VARCHAR2(9),
exch_rt_eur NUMBER,
exch_rt_usd NUMBER);
CREATE OR REPLACE TYPE exch_tbl AS TABLE OF exch_row;
In Oracle 12C it is now possible to select from PL/SQL tables that are defined in a package spec.