What does Genesis 43:32 mean?
Though his brothers still do not recognize him (Genesis 42:8), Joseph is treating them as honored guests. He is now the second most powerful man in Egypt (Genesis 41:44). As part of his testing and reuniting with the family who sold him into slavery (Genesis 37:24–28), Joseph is hosting a banquet for them (Genesis 43:16–25). The noon meal is served to three distinct groups, who all sit separately. First, Joseph sits and eats alone. The brothers sit together. Finally, the Egyptians sharing in the meal sit in a third grouping.Apparently, Egyptian custom did not allow for sharing a table with Hebrews or perhaps any foreigners (Genesis 46:34). Joseph's seating might be for that reason: the Egyptians know he is a Hebrew. However, Joseph was also well-integrated into Egyptian society (Genesis 41:42, 45, 50), so this might not have been an issue for him. Another possibility is that Joseph was seated separately as a sign of his status and power. Perhaps he could not be seated with "common" people, even Egyptians.
Regardless of the exact reasons, all these men are in the same room, but likely at entirely separate tables. Joseph will test them, in a sense, by greatly favoring Benjamin (Genesis 43:34), perhaps gauging their reaction.