When Hamlet meets the soldiers while he is sent to England, one soldier, being questioned by Hamlet where and against whom they go to fight, answers him: "Against some part of Poland." Hamlet's following speech including the words "which is not tomb enough and continent to hide the slain" does not make any sense here. The soldier did not tell him what part of Poland he referred to. Therefore, Hamlet does not know this. And Poland is not that small.