One of the more annoying things you might start to encounter, especially when building a new app or table, is that every time you create a sys_dictionary record to add a field, that field is automatically added to the bottom of your default form, almost never what you actually want to happen.

The solution to this is thankfully very simple, find the business rule in your instance named:

Add New Column To Form Section

On the Dictionary (sys_dictionary) table, and disable it.