The Gemara assumes that anything that is necessary for the meal would not be considered an interruption, but defining what is considered necessary for the meal is the subject of dispute. According to Rabbi Yohanan, for example, asking for salt would not be considered an interruption. According to Rav Sheshet, even saying “mix food for the oxen” is not an interruption. The Gemara explains that this follows the teaching of Rav Yehuda in the name of Rav who taught:
One is prohibited from eating before feeding his animals, as it is stated: “And I will give grass in your fields for your animals” first and only then: “And you shall eat and be satisfied” (Devarim 11:15).
In the verse, preparation of food for one’s cattle precedes preparation of one’s own food. Consequently, it is considered part of the preparation for one’s own meal.
The Gemara continues by clarifying the importance of salt at a meal –
Rava bar Shmuel said in the name of Rabbi Ḥiyya: One who breaks bread is not permitted to break it until they bring salt or relish before each and every one seated at the table. However, the Gemara relates that Rava bar Shmuel himself happened to come to the House of the Exilarch. They brought him bread, which he immediately broke, without waiting for them to bring salt or relish. They said to him: Did the Master reconsider his halakhic ruling? He said to them: Although poor quality bread requires salt in order to give the bread flavor, and therefore one must wait before breaking bread, this refined bread served in the House of the Exilarch needs no salt, and does not require waiting.
The simple reason that salt is essential to the meal is that the salt is necessary in order to give the food some taste, and consequently, refined bread does not require salt. Some explain based on the Gemara’s statement that a person’s table is like an altar; one must place salt on the table, just as salt is placed on the altar. The Rosh adds that salt serves as a reminder of the “eternal covenant of salt” (Bamidbar 18:19) between God and the Jewish people and protects the Jewish people from its detractors.