Insert value into other new table

Hi,
I ask if there is a method to insert values of an existing table into a new table that don't have values. I see that there is db.update, but I don't know how to use for this specific use.
My purpose is to display this new table in a report, because I don't need of all the fields of the existing table but only some that I have already put.
Regards,
RavCoder