Doersn't Golden Time happen is all state primaries, at least at infant stage?
Sometimes called Continuous Provision maybe?
At the school I work at it involved the year group haveing free access to either of the 3 Y1 classrooms. There are a range of activities laid out on tables, in play corners on the floor - adnd in summer some outside time too I believe.
Activities include reading books, colouring and drawing, building blocks, jigsaws, computer time, board games, home corner, role play section, puppets, etc.
All the rooms are supervised by teachers and TAs who are engaged with the children in activities. Some of the teachers are involved in PPA time at this time too, so they will be absent but their place covered by another memeber of staff to ensure all ratios, etc are met.