That list at the side of the site displays what maps all Feralheart players are currently in, so yes, as DelightfulRevenge stated, they are real.
The catch is, they are not all public maps; some are made by Feralheart players for roleplaying purposes and other various reasons. The number of players increase/decrease at certain periods, usually depending on popular time zones and other factors, so it's natural to see lower numbers sometimes, or even very few maps listed, since maps with no players in them at that moment are not counted.