In this area you define how to use the playlist feature. There are two playlists to choose from: a list of favorite files that you create for example by dragging files from the Explorer at the bottom; or simply the files in the Explorer list. You can define the Playing order and repeat. In "playlist options" you can tell SynthFont to start playing a file when you have double-clicked it to open it in SynthFont. Additionally, you can ask SynthFont to keep this page open when starting to pla, and not switch to the "Plug & Play" page.
This is the list of your favorite files. You can have several lists stored in several Playlist files.
This is the Explorer view. It is very similar to the standard Windows' Explorer. Here you can navigate among folders where you keep files of interest - MIDI files, Arrangements and SoundFonts. Note the column to the right, showing the name of an arrangement found for a particular MIDI file, If you double-click on the MIDI file, the arrangement will be opened instead.