Traditionally these are the six or four people that carry a coffin out from a funeral. The number depends on fashion, but also on practical considerations such as; how the coffin is carried -at shoulder or waist height, the age and weight of the deceased and the number of people wanting to participate.
If the deceased is buried then there may also be pall bearing to the grave as well as out from the church. In some countries, the moving of the dead is done by machines but pall bearing remains symbolic in many European cultures and is still organized to be part of a ceremony to show respect.
Pall bearing itself is one of the less familiar rites of passage. Until recently, I'd been to several funerals, and even spoken at one early in life, when my best friend in high school foolishly killed himself by falling off an escalator barrier in a shopping complex. But it wasn't until my grandfather finally died at ninety that I found out what pall bearing was about.
The first thing that struck me is how heavy the dead are. Dead weight. My grandfather, originally a large belly-some man, by his death, had wasted away to a mere 7 stone. But caskets are such a mass of woody sobriety like no other box, they often weigh more from the wood they are made of than the flesh they contain.