Speaking from the Australian version of the show.
We weren’t allowed any electronic devices, but could bring books (had to carry it in your bag though). On flights we would just watch the in flight entertainment or sleep.
Depending on the schedule, you rarely get many days of doing nothing. If we did have a day off we had to stay in our rooms and were let out from small periods with handlers. For the first few days they tried to keep everyone from talking off camera, but eventually stopped caring so we could all hang out in the hotel lobby or by the pool if we had one.
You were honestly exhausted after most legs and would just want to lay in bed anyway and do nothing. If it was a nice hotel we would have a tv with some English channels we could watch.
Typically though if a leg finished in the arvo, would spend a fair amount of time waiting for our turn for confessionals, then the confessional process took like an hour, then you’d have dinner (sometimes buffet, sometimes room service) and then go to bed.