On 107b, the Gemoro discusses Agripas Hamelech who would not eat in the
early afternoon of Erev Pesach. and the Rashbam explains that his meal
would undoubtably continue into the Sha'a Asiris. Mogen Avrohom and Mishna Brura bring this as Halocho in Hilchos Erev Pesach.
My question is whether this halocho applies to the general rules of
eating before Shabbos and Yom Tov. We know that when Yom Tov falls after
Shabbos, many people are particular to have Shalos Seudos before the
Sha'a Asiris (see Biur Halocho at end of Hilchos Yom Tov). However,
I don't think people are makpid to FINISH their meal before Sha'a Asiris.
Mark Bergman
Indeed, in Hilchos Pesach, OC Siman 471, the Magen Avraham #1 and the Mishnah Berurah #9 rule like the Rashbam that one may not begin a Seudah before the end of the 9th hour with the intention of continuing into the 10th hour.
I could not find anyone who mentions this Din on Erev Shabbos. Perhaps on
Erev Shabbos there is room to be more lenient as Meikar ha'Din one is allowed to begin eating a small meal even after the 10th hour. Of course it would always be preferable to finish as early as possible to ensure that the
Seudas Shabbos will be eaten with a good appetite.
Kol Tuv
Ilan Segal