"But , Savta, Shavuot is the time when the Torah was given to the Jewish nation. How can I eat at a time like this ? I want to be completely spiritual, to learn Torah."

But Savta is right once again ! It is important for Sam to eat on Shavuot. Regarding other Festivals there is a Talmudic debate as to whether there is a mitzva to enjoy food and drink or if may choose to forgo eating and instead spend the entire day in Torah study and prayer. But on Shavuot all Talmudic sages concur that it is a mitzva to enjoy food and drink. Why? To celebrate the day of the Giving of the Torah.

You may wonder, why celebrate such a spiritual event by eating and drinking? Wouldn't a more appropriate way to honor the Torah be to focus on it to the exclusion of all else? The great medieval scholar Rashi explains that we rejoice with food and drink to demonstrate that the Torah is pleasurable and beneficial to the Jewish nation. The Torah is not only pleasurable and beneficial to the soul, but to the body as well. So listen to Savta, Sam, and eat and enjoy!