It contains the following columns:

Setting thread_poll_exact_stats will provides better queueing time statistics by using a high precision timestamp, at a small performance cost, for the time when the connection was added to the queue. This timestamp helps calculate the queuing time shown in the table.

Setting thread_pool_dedicated_listener will give each group its own dedicated listener, and the listener thread will not pick up work items. As a result, the queueing time in the table will be more exact, since IO requests are immediately dequeued from poll, without delay.