How can I allow users to edit a field on a particular model that is accessed via lookup?

Best way I have found is to add a row action that opens the record you want to edit in a pop up or sliding panel. You will need a separate model based on the object in the look up. Your row action will first activate and set the value of a condition on that model limiting it to the appropriate ID. Then requery the model, then open the pop up to display a table or field editor on the model.