To enlarge the screen and enlarge the cards (by doing so the avatars will disappear and only the nicknames will remain), click on the User Options button (indicated by the red arrow in the image below)

then he must click on General (indicated by the red arrow in the image below);
then click on the button on the right of the word Full screen table (indicated by the blue arrow in the image below) and turn it green (in the image below it is still red)