We have "The hoard was buried as an oak box or small chest filled with items in ..." and later "....amounting to a total of 3.5 kilograms (7.7 lb) of gold and 23.75 kilograms (52.4 lb) of silver.[23]  It had been placed in a wooden chest, made mostly or entirely of oak, that measured approximately 60×45×30 cm (23.6×17.7×11.8 in)...", which I think covers the ground.  As a "chest", it is certainly "small" I think. Much below that & you have a box or casket.