Hello @Petr Maslak
In this page, you can only fill in the WHERE clause. And it is paged to protect both the Azure service and the user in case there are a million users.
If you fill in:
You get (the same) page list of all edge devices.
An alternative is the Query Explorer, seen in the main menu of the IoT Hub :
Notice the 'unlimited' option... This only shows the device twin of edge devices, not the module twins.
You can also check out the underlying IoT Hub Rest API eg. 'Get Devices'.