If you are traversing JTable (not editing) and hit Esc key the event is consumed by JTable. It happens because the "cancel" action is enabled in all situations. It should not be enabled while you are not editing.
javax.swing.plaf.basic.BasicTableUI.CancelEditingAction is the culprit.
Fix for similar problem was already applied in BasicTreeUI between JDK1.3 and JDK1.4. Please do the same for JTable. Thanks.