Jamieson, Fausset and Brown on Genesis 43:16

16. ruler of his house--In the houses of wealthy Egyptians one upper man servant was intrusted with the management of the house (compare Ge 39:5).

slay, and make ready--Hebrew, "kill a killing"--implying preparations for a grand entertainment (compare Ge 31:54; 1Sa 25:11; Pr 9:2; Mt 22:4). The animals have to be killed as well as prepared at home. The heat of the climate requires that the cook should take the joints directly from the hands of the flesher, and the Oriental taste is, from habit, fond of newly killed meat. A great profusion of viands, with an inexhaustible supply of vegetables, was provided for the repasts, to which strangers were invited, the pride of Egyptian people consisting rather in the quantity and variety than in the choice or delicacy of the dishes at their table.

dine ... at noon--The hour of dinner was at midday.