http://www.reddit.com/r/AskHistorians/comments/26vne0/how_did_the_spoon_and_fork_come_to_be_is_it_a/

Recent related thread here.

Spoons and Knives - go back to prehistory if you count basic scooping and cutting tools used for eating.

Forks - as a kitchen tool these go back to at least the 4th millennium BC, examples found in Greece, Egypt and Turkey but not used as an eating utensil until the middle ages in the Arab world and not until the Renaissance in Western Europe.

I'm still waiting on someone more qualified but I do know spoons and knives were more prevalent during the Middle Ages both because of the increased use of stews and braises but also because the fork resembled the pitchfork that was associated with the devil.