I have several tables that already exist in my database. Some of them have quite a few columns.
I want to make some stored procedures to do a merge statement with these
In SQL Server Management Studio you can right click a database, and under TASKS choose to script the database. Choose Tables only, and then the tables you're interested in.
It doesn't give you a one stop shop to what you want, but it can script many tables quickly and easily. And then allow you to do a bit of find-and-replace to get what you need.