All users, except for collaborators on Enterprise and Business accounts, can add custom fields to the table portion of the Gantt chart.
Click the gear icon in the table’s upper left-hand corner.
Check the box next to any custom field (or group of fields) you want to see or uncheck the box next to any custom field you want to hide.
Note that you can only add custom fields that are shared with you.
By default, only custom fields from the current folder/project/space are shown. To add custom fields that are available to you from another folder/project/space:
Click the gear icon.
Click Manage Custom Fields.
Click the +New field button.
From the drop-down menu select the needed custom field.
When all the necessary fields are added to the list, click Done.
To delete custom fields from the table, click the gear icon and uncheck boxes next to custom fields you'd like to remove.