They separately served Joseph, his brothers, and the Egyptians. They ate separately because the Egyptians would not eat with the Hebrews, since that was detestable to them.
Jewish Publication Society of America Version (JPS1917) - Genesis 43:32 >And they set on for him by himself, and for them by themselves, and for the Egyptians, that did eat with him, by themselves; because the Egyptians might not eat bread with the Hebrews; for that is an abomination unto the Egyptians.