Keychain Entries

Can anyone explain why my server keychain contains more than 50 Pubic/Private keys (and seems to expand everyday) that are not part of a Digital Certificate? The keys all seem to be duplicates of each other and since I am a one-person establishment why do I need all those keys? Can they be safely deleted?

I generally understand how public and private keys are used, but for the life of me cannot determine why Lion Server is producing them in such quantity.