gunakan row_number berfungsi untuk memberikan nomor urut baris Anda
insert into Table1 (column1,column2)
select
(select max(column1) from Table1) + row_number() over (order by T2.anotherColumn),
T2.anotherColumn
from Table2 as T2
atau versi yang lebih aman (ini akan berfungsi bahkan jika Anda tidak memiliki baris apa pun di Tabel1):
insert into Table1 (column1,column2)
select
isnull(T1.m, 0) + row_number() over (order by T2.anotherColumn),
T2.anotherColumn
from Table2 as T2
outer apply (select max(column) as m from Table1) as T1