Dive history is a summary of all the dives done with your Suunto D5. The history is divided according to the dive mode used for the dive. Each dive type summary includes the number of dives, cumulative dive hours and maximum depth reached in all dives of that dive mode.
Enter History under General » About D5:
If there is more history information available than can be shown in a single screen, you can scroll through the additional information with the upper and lower buttons.