In your case, I feel like creating Workflow might be the easiest option to get started as you don't really want to update JMP table but rather always re-create new table.
Create new workflow
Start recording actions
Here I have excel opened and I have added new column
You can stop recording at this point, as I feel like this is all you need.
Then you can save your workflow and just rerun it to create new table whenever you need one.
-Jarmo