What about public eating?

Listen, this is a very important question because the way a Talmid Chacham conducts himself in public is vastly different from the average person. The halacha is clear: a Talmid Chacham should not eat in front of people. Period. This is not a suggestion - this is halacha. The reason is twofold. First, when a Talmid Chacham eats with his students or in front of the public, they start to befriend him. Once they befriend you, they look at you very differently. You're going to listen to a rabbi, but you're not always going to listen to a friend. That's just the reality. The moment people see you eating like them, they start thinking of you as if you're just like them. They won't listen to you, they won't learn Torah from you, and they'll disrespect you. Second, a person at that level doesn't want other people to see them fulfilling their desires. Even though eating is necessary, it's still a physical need, and the Talmid Chacham is trying to minimize the focus on the physical and maximize the spiritual. This is why many of the tzaddikim, even to this day, don't eat in front of people in general. Ever. I know rabbis who run shuls where there's food every single day, especially on Shabbat - everyone else is eating, but they don't eat. They don't eat in front of strangers. When they do eat, it's usually with specific people, sometimes in the corner, not necessarily in front of people. Now, let me be even more specific. The Rambam in Hilchot Sanhedrin, Chapter 25, the first four halachot, writes clearly: if performing work in public is forbidden to a Talmid Chacham, certainly it is forbidden for him to eat and drink or to become intoxicated in the presence of people at large, in the gatherings of the common people, and in friendly get-togethers. Woe to those judges who conduct themselves in this manner, disgracing the Torah of Moshe, debasing its judgments and lowering them to the earth. So stop expecting rabbis to come to every bar mitzvah and bat mitzvah and brit milah and expect them to eat, have a drink, and do l'chaim. This is not the way that a rabbi is supposed to act, and if he is doing it on a regular basis, you may want to seek a replacement. Why? Because he became one of the community, not fit to be a leader. There was one of the great tzaddikim who had a custom that he took upon himself to never eat or drink in front of people - similar to what the Chazon Ish practiced. He took it to an even higher level. After praying in shul, there would be lines of people asking him questions all morning into the afternoon, 12, 1 o'clock. The Rabbanim would have to get involved and say, "Please, let the Rabbi go so he can drink. He hasn't drunk since the morning because he doesn't drink in front of people." Now, to be clear about the distinction: if you're a regular person and you go to a restaurant and eat in the restaurant with good manners in your corner, there's no problem. Some sages are even strict on that, saying you should eat in the corner without other people seeing you. But as far as halacha is concerned for a regular person, there's no problem eating at a proper place designated for eating. But a Talmid Chacham? That's a different story entirely. The Gemara even says it's better for a Talmid Chacham to eat next to a dead body with a separation than to go outside and eat where people can see him. That's how serious this is. This is about kavod, about honor, and about maintaining the respect necessary for Torah to be taught and received properly. Remember, a Talmid Chacham is a living Sefer Torah. When a regular person thinks of Torah, he has to visualize something alive - and that's the Talmid Chacham. If the Talmid Chacham acts like everyone else, eating in public, socializing with everyone, then the honor of the Torah itself is diminished. This is why these guidelines exist and must be followed.