Fork

Two pronged forks were used in many European cultures (including the English) since before the 12th century (I believe) for the carving of meat. Each family might have one of two such carving forks for use at the table (ie. used only to chop up the meat, didn't get anywhere near anyone's mouth).

The earliest evidence of personal eating forks I've come across is in 12th Century Italy (well OK, Venice, since Italy didn't exist yet). Before this time eating utensils were a spoon and a knife.

However, forks were rather slow to take off. By the 14th Century, France had adopted the fork, but England held off adopting these inventions of the hated foreigners until after the time of Henry VIII.

In later medieval times, western European people primarily used two pronged forks, like a modern carving fork, but smaller. Many people in the SCA consider any fork with more than two tines to be out of period, but period examples of forks with more tines do exist. Three, four, five and even seven-pronged forks are extant. If you're looking to buy a two pronged fork, they turn up regularly in op-shops, sometimes even in sets of 6, and are quite cheap.

Since it's rather difficult (and probably non-period) to eat without using your fingers with only a knife and a spoon, a serviette (or at a pinch a tea towel) is an extremely useful item, as it prevents getting nasty hard to remove grease stains on your garb from the roast chicken and making the hospitaller angry (if you borrowed the garb).