When using a pc/laptop:
To see all hands at a table: click once with the mouse on the alias of a seated player and confirm by clicking the display Spectate this Table from the **** (= North/South/East or West).
You can also choose Kibitz **alias** and you will see the same as the player you are kibitzing.
When using a tablet:
Select a table you want to spectate and then touch the eye symbol at the top (next of the refresh button)