To eat with someone is to share close fellowship. It is a sign that peace exists between those sharing the meal. As far as the "saw God" as opposed to the "no one can see God:" the phrases are ellipses. They are not complete in and of themselves but they require the broader context to understand their meanings.
That's why some people will criticize the Bible as being "inconsistent" or "contradictory." Statements are lifted out of their surrounding context and then compared. We need to get the whole context and compare it.
Exodus 24 tells us how the children of Israel were brought into fellowship with the living God.
Exodus 33 tells a different story giving us another perspective on the multifaceted theme of what it means to "see God."
God does invite us in and withholds no good thing from us. However, after all is said and done - we still haven't seen everything or discovered all that there is to know.