The recommended way of using the data editor is when you have 12 or fewer lines of data to edit. If it gets larger than this you should go to the data display screen and use SHIFT-Click to select a group of entries and delete them and try again. And if your 12 or fewer lines are all of the same word, delete all the entries for that word and start over. The reason I recommend this is because the data entry GUIs provided guide and correct the process in a way the raw data does not. The main text screen in the middle is editable and will update to the database when the GUI is exited. For info on SQL consult the documentation provided with your version of PostgreSQL, usually in the directory "/usr/share/doc".