insert into t2(name,pay1,pay2,pay3)
select name,pay1*100*0.5,pay2*200*0.5,pay3*300*0.5 from t1

------解决方案--------------------
oracle的话
insert into t2(name,pay1,pay2,pay3)
select name,pay1*100*0.5,pay2*200*0.5,pay3*300*0.5 from t1  where rownum<=100

sqlserver
insert into t2(name,pay1,pay2,pay3)
select top 100 name,pay1*100*0.5,pay2*200*0.5,pay3*300*0.5 from t1

------解决方案--------------------
SQL code

insert into t2(name,pay1,pay2,pay3)
select name,
pay1*100*0.5 as  pay1_1,
pay2*200*0.5 as  pay2_2,
pay3*300*0.5 as  pay3_3 
from t1