I have a form with an input table, with 6 columns numeric.

I have a form with an input table, with 6 columns numeric. Is there a way to limit it to only 1 numeric number per field?

Can you please share the form where you got this table? If you are looking to setup different type of fields per column, we would suggest you to use a configurable list widget instead: https://www.jotform.com/help/282-How-to-Set-Up-the-Configurable-List-Widget