1)
What is "Chamor Lechem v'Nod Yayin"?
1.
Radak, Targum Yonasan: It is a donkey laden with bread and a flask of wine.
2.
Radak: Some say that Chamor is a collection. This is like "Chamorasayim" (Shoftim 15:16), "Chamarim Chamarim" (Shemos 8:10).
2)
Why did Yishai send food to Sha'ul?
1.
Malbim: The custom is was to bring a gift when seeing a king or great person.
