안녕하세요 

방법이야 여러가지가 있겠지만 이런식으로 가능합니다.

수고하세요

declare @t1 table (id int)
declare @t2 table (id int)

insert into @t1 values(1)
insert into @t1 values(2)
insert into @t1 values(3)
insert into @t1 values(4)

insert into @t2 values(1)
insert into @t2 values(2)
insert into @t2 values(3)
insert into @t2 values(4)

select * from (select top 2 id from @t1 order by id desc) t
union all
select * from (select top 2 id from @t2 order by id desc) t2