Give select grants on all tables in my schema

 The following code gives the select grant on all the tables in your schema to "test2" user.

BEGIN

FOR t IN (SELECT * FROM user_tables)

LOOP

EXECUTE IMMEDIATE 'GRANT SELECT ON ' || t.table_name || ' TO test2';

END LOOP;

END;

/

(last slash "/" is important)

Just a copy from;
https://sites.google.com/site/nazmulhudadba/grant-select-on-all-tables-in-a-specific-schema-to-a-user