The Fork is a emergency starting weapon which can be found in most houses. Out of all the basic cutlery (butter knife, fork, spoon), the fork, similar to the spoon is a extremely low damage weapon which cannot perform the insta-kill jaw stab which comes with the Butter Knife or other advanced knives. Every hit on a zombie reduces the item condition falling by 1, and having a max of 3, it means you only get 3 hits with the fork before it breaks.
The fork is a single attack weapon, meaning it can only concentrate on one zombie at a time, attacking two at a time is risky as only one zombie will be stopped per hit and the other could get in close enough to damage the character.
One if the benefits of the fork is that it is plentiful in the game world and is quite light. The fork cannot be repaired. It is recommended you use the Butter Knife compared to the fork if truely out of weapons at the start.