Prova detta
with CTE as
(SELECT
a.Title
,a.Id
FROM
TableA
)
,CTE2 as
(SELECT
b.Title
,b.Id
FROM
TableB
)
INSERT INTO @myData --- insert statement goes here after CTE
Select * From CTE
union all
Select * From CTE2
Select ROW_NUMBER() OVER(ORDER BY GetDate() DESC) AS RowId, x.*
From @myData x
order by x.Id desc