The fonts thing just means you can easily access / iterate through all the fonts in the font table via an index number instead of having to type out the full name of whatever you are trying to access. It's not just for fonts, it's for all VisObj data structure entries that fall under the type table.
i.e: Characters, Actions, Interfaces, etc. etc.
Let's say our protagonist is the first one in the characters list, it's index should equal 1 (unless Simon has allowed index 0 - in Lua tables the index usually starts at 1). So, we could print the name of the character to the log, like so...
print( Characters:getName() )
P.S: I've not actually tested it, so it's just a guess on my part.