The dates view extends the events view. Since Matukio 3.1 an event can have multiple dates, here you can manage them.
When you click on the event title you can edit the date, a click on the id brings you directly to the event to which the date belongs. If you click on the number of bookings you come to the bookings page, where you can see / add new / edit all bookings of the date! The status indicates if the date is still published and and has not yet taken place. Availability tells you if the date is still available and has not been canceled. The Book column shows you if the event is still bookable (has free places and booking has not been closed yet). If you have enabled the waitinglist (if the event is overbooked) you see a yellow light here if the event is full, else you see a red one indicating that no more bookings are possible.
You can also unpublish / publish or cancel / reactivate dates here - the participants will automatically notified about that (you can deactivate that in the settings).