Just like you read any other transit schedule in the world. The column on the far left is a list of stops. Each column is one bus connection and the times in that column correspond to the time (in 24 hr format) that bus stops at that stop. If the times go down to a stop and then continue in the next column, it indicates that there is probably a change of buses at that stop.
Page 1 says "Garmisch-Partenkirchen - ... - Füssen". Those are the buses from GaP to Füssen on workdays (Montag - Freitag ausser Ferientag [Monday - Friday except recognised holiday]). Page 2 is Füssen to GaP on workdays. Page 3 and 4 are for Saturday (not holiday) and Sundays/Holidays.
On page 2 you see a bus leaving Füssen Bahnhof at 8:05 and going straight through to GaP Bahnhof (Bf) at 10:13.