The main data source for new JMP users will always be Excel. These can be messy, and probably used as database with manual input for KPI tracking, for example.
However, neither the Excel add-in, nor the Excel wizard provide a simple way to update file from its source.
This is a common request that can be found in this forum, multiple times, and all of them require scripting (see examples below).
You can see the understandable response of beginners, that are drag into a complex solution to a simple request.
Updating columns, adding new rows, adding new columns, all of these are complex concepts that require several steps and getting into automation via JSL or Automation Builder.
JMP needs to include a wizard to automatically generate a script that reads and updates the current data table in place.
https://community.jmp.com/t5/Discussions/Automatically-update-quot-source-quot-file/td-p/324299
https://community.jmp.com/t5/Virtual-JMP-Users-Group/How-to-update-a-JMP-data-table-to-reflect-Excel...
https://community.jmp.com/t5/Discussions/How-do-I-automatically-update-JMP-data-table-while-populati...