Question: Is one permitted to eat a bread meal after halachic midday on Erev Shabbat (Friday afternoon)?
Answer: The Gemara (Gittin 38b) states that there were two wealthy and important families in Jerusalem and both of them sinned to the extent that they were eventually uprooted from the world. The first family would hold a large meal on Shabbat afternoon at the same time the entire community would file into the Bet Midrash to study Torah; as the rabbi would sit to lecture on Torah, they would sit down to eat. The second family would hold a large meal on Friday and as a result, the entire family was full on Shabbat night and they would not eat with enjoyment as prescribed by Halacha. Both of these families eventually perished.
The Poskim explain that the prohibition to hold a large meal on Erev Shabbat refers to a meal one is not accustomed to eating during the rest of the week. For instance, the custom that some families have that the entire family gathers in the grandmother’s home on Friday to eat a large meal and partake of what she has cooked is contrary to Halacha since this is an affront to the honor of Shabbat since one will not be able to enjoy the Shabbat night meal properly as a result. This is especially true during the winter when the days are short.
However, a meal which is normally eaten during the rest of the week, such as if one always eats a meal at four o’clock in the afternoon, may be eaten on Erev Shabbat as well. Nevertheless, it is a Mitzvah to abstain from eating such a meal beginning from the ninth hour of the day (meaning that the day is divided into twelve parts from sunrise to sunset and each one of these parts is one seasonal hour; from the ninth seasonal hour of the day, one should not eat anymore until nightfall). Maran Rabbeinu Ovadia Yosef zt”l writes, as follows: “Although halachically speaking it is permissible to eat until sunset, nevertheless, this should only be done as needed and only occasionally; however, to do so on a constant basis is forbidden beginning from the ninth hour of the day, for doing so constitutes a disrespect for Shabbat.” (Chazon Ovadia-Shabbat, Part 1, page 32)
The Mishnah Berura (Chapter 249) states that if one knows that eating or drinking will cause one to be full at night, it is a Mitzvah for one to abstain from eating or drinking profusely even before the ninth hour of the day, especiually during the winter months, for we can see that one who eats or drinks profusely (especially wine) on Friday is not hungry at night. It is therefore a Mitzvah to abstain from such eating and drinking.
Summary: A meal normally eaten throughout the rest of the week may be eaten on Friday as well. A meal not usually eaten during the rest of the week may not be eaten on Friday, even at an early hour of the day. Beginning from the ninth hour of the day, i.e. approximately three hours before sunset, it is a Mitzvah to abstain from eating even a small meal. Nevertheless, eating small things or tasting some of the Shabbat food and the like is completely permissible.