Вы хотите full join
. Вы можете эмулировать это в MS Access, используя:
select t.CustID, t.DATE, t.Exp1, t.Exp2, s.tem1, s.tem2
from TableT as t left outer join
tableS as s
on t.CustId = s.CustId and t.date = s.date
union all
select s.CustID, s.DATE, null, null, s.tem1, s.tem2
from tableS as s left outer join
tableT as t
on t.CustId = s.CustId and t.date = s.date
where t.CustId is null;