サブクエリでそれを行うことができます:
UPDATE Table3 t
SET t.temp = (SELECT s.result+p.resource
FROM table1 s INNER JOIN table2 p
ON(s.email = '[email protected]'))
Table3にまだデータがない場合:
INSERT INTO Table3
(SELECT s.result+p.resource
FROM table1 s INNER JOIN table2 p
ON(s.email = '[email protected]'))