If you need to include a column in your gradebook for an activity that takes place outside of Moodle, the recommended procedure is to Add a Grade Item to the Gradebook.
It is also possible to add columns in the gradebook for text only. This option allows you to have an item in the gradebook that will not affect the grade calculation but will communicate feedback to the student. You do not enter text in the grade field, but rather enter text in the feedback area.
Note: This is not a recommended procedure because of the display limitations for the grader and the student. However, for some grading situations, it is an ideal option.
Adding a text item column to the Gradebook in Moodle 3.2
Go to the course homepage.
Find the Administration block:
Click Gradebook setup.
Click Add grade item .
Enter an Item Name.
Click Show more… to see the options.
Change Grade type to Text.
Scroll down and click Save changes. The new item will appear at the bottom of the courseassignment table.