the leviton bridged telephone board has each pair of the 4 pair connecting block 'bridged' to all the pair directly below it on the panel. If you were to punch down a cable pair on the first pair of the top block, it will be connected to all the other lines in teh first row.
For example: Lets say you have a Cat5e cable from the phone company NID to your leviton can. At the NID the blue pair is connected to line1, the orange pair to line2 and the green pair to line3. The cable end in the enclosure should be terminated on the bridged panel to the corresponding color coded positions. I usually use the top or bottom block for incoming lines. I would also go ahead and puch down the brown pair even though it not connected in the NID. To deliver line1 phone service to any of the outlets in the house, puch down the blue pair of the cable from the outlet on any available blue pair port on the panel. For line2 puch the blue pair from the outlet to any orange pair on the panel. For line3 connect the blue pair from the outlet to any green pair on the panel.