To insert fields into database tables in phpMyAdmin, first log in and follow the steps:
1. Select the database on the left-hand side which contains the table where you wish to add the fields.
2. Click on the table on the left-hand side that you wish to add fields to.
Note: You can add fields at the beginning and end of a table or after an existing field.
3. Enter the position in the table of the new field (remember to select the correct field in the drop down, if you wish to add the field after an existing one.)
4. Click 'Go' and then enter the details of the new field and click 'Save' when finished.