The term 'timetable stats' refers to the statistics associated with a timetable. ETAS is an acronym for Estimated Time of Arrival, which is a statistic that is used to measure the accuracy of a timetable. It is calculated by taking the difference between the actual arrival time and the scheduled arrival time of a train or bus. ETAS is an important statistic for measuring the reliability of a timetable and can be used to identify areas where improvements can be made.