SQL Server 2017

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select * 
into #t1
from(
select 'va1'c1,'vb1'c2,'vc1'c3 union all
select 'va2'c1,'vb2'c2,'vc2'c3 union all
select 'va3'c1,'vb3'c2,'vc3'c3 union all
select 'va1'c1,'vb1'c2,'vc1'c3 union all
select 'va2'c1,'vb2'c2,'vc2'c3 union all
select 'va3'c1,'vb3'c2,'vc3'c3 union all
select 'va1'c1,'vb1'c2,'vc1'c3 union all
select 'va2'c1,'vb2'c2,'vc2'c3 union all
select 'va3'c1,'vb3'c2,'vc3'c3 union all
select 'va1'c1,'vb1'c2,'vc1'c3 union all
select 'va2'c1,'vb2'c2,'vc2'c3 union all
select 'va3'c1,'vb3'c2,'vc3'c3 union all
select 'va4'c1,'vb4'c2,'vc4'c3 
)t

select *
into #t2
from #t1
where 0=1

;with
tmp1 as
(
    select t1.*,
           ROW_NUMBER()over(partition by t1.c1 order by(select null))r
    from #t1 t1
    left join #t2 t2 
      on t1.c1=t2.c1
    where t2.c1 is null 
)
,tmp2 as
(
    select 0 n,*
    from tmp1
    union all
    select n+1 n,t1.c1,t1.c2,t1.c3,t1.r
    from tmp2 t1
    join tmp1 t2
      on t1.c1=t2.c1
     and t2.r=t1.r+1
    where n<10
)
MERGE #t2
USING tmp2
  ON #t2.c1 = tmp2.c1
WHEN NOT MATCHED THEN
  INSERT VALUES (tmp2.c1, tmp2.c2, tmp2.c3);

SELECT @@ROWCOUNT

(No column name)
103