Those are metronome indicators and tell you the tempo that the piece is to be played.
So for instance, quarter note symbol>=124 means that if you set a metronome at 124 bpm (beats per minute), then each quarter note would be played simultaneously with the click of the metronome.
The reason that some have dotted quarters is because they are a compound meter, 12/8 in the example. 12/8 can be expressed as 4 dotted quarter notes (3 eighths) instead of 12 eighth notes. It's just easier to count 12/8 this way, so the tempo reflects this counting.