CREATE OR REPLACE FUNCTION grant_tables(priv text, dbuser text)
RETURNS INTEGER AS $BODY$
DECLARE
  obj  record;
  num  integer;
BEGIN
  num:= 0 ;
  FOR obj IN SELECT tablename FROM pg_tables WHERE schemaname = current_schema() LOOP
    EXECUTE 'GRANT ' || priv || ' ON ' || obj.tablename || ' TO ' || dbuser;
    num := num +  1 ;
  END LOOP;
  RETURN num;
END;
$BODY$ LANGUAGE PLpgSQL;


SELECT grant_tables('ALL', -- права: ALL, SELECT, INSERT ....
                    'test'); -- USER