This was a large multi-function room capable of seating the bulk of the population of the house. The family would sit at the head table on a raised dais, with the rest of the population arrayed in order of diminishing rank away from them. Tables in the great hall would tend to be long trestle tables with benches.
Protozoan Cyst is a defense mechanism in the Protozoan family. It takes this form according to the conditions of the host. A change in pH, a change in oxygen supplies, anything that trigers the genetic mechanism. The cyst is evacuated trough the sediment. You could say that Cyst are a defense mechanism.
Cyst (Definition) A cyst is a structure or mass that consists of a cellular lined sac. It is typically filled with fluid but may be filled with solid material. It can be congenital, traumatic, or acquired. They may develop nearly anywhere in the body and usually require complete excision for eradication or they are likely to recur. Fluid filled sacs that are not cellular lined may be called pseudo-cysts.