The dining room in his family's home has come to symbolize safety, a refuge from the real world.  It is kind of a retreat, back to the security of childhood where Leper knows all his needs will be met, and things are comfortable and predictable.  Leper says, "you aren't lost for something to do in dining rooms...it's in the living room where people can't figure out what to do with themselves...people get problems in living rooms".  In comparing his choice of the dining room over other rooms, Leper is giving double meaning to the term "living room".  It is a room in his house, but it is also "living" that he has not been able to handle.  He is hiding in the safety of the dining room because "living" in the real world, which in his place and time is the Army and the war, is too difficult. 

The dining room in Leper's house is a place where he has control.  He sits "at the had of the table in the only chair with arms, his father's chair".  Like a patriarch, he can direct what happens around him, unlike in the real world, where he is at the mercy of forces which surround him.  Also, in the dining room, as exemplified by the dining table with the captain's chair, there is the comfort of family and the security of tradition.  Everything is familiar; it is a shelter from the cold realities of the outside world (Chapter 10).