I learnt in mesechas pesachim perek 10 daf 114 amud 1 in the gemorah the reason bais shamai holds you bless the day then the wine is because the day makes the wine come and rashi says on this that its talking about before the seuda inferring that they usaully dont drink before the seuda and here we learn in the mishna that they do drink before the seuda? i dont know if a good question but i was wondering if you knew the answer.
hananiah lasker, philadelphia,pa ---- amsterdam,holland
Actually your Gemara in Pesachim is also a Mishnah in B'rachos (51b), which is followed almost immediately with a ruling which refers to the wine that they used to drink before the meal.
Clearly, the first ruling is speaking about Shabbos and Yom-Tov, as Rashi explains, and the second one about weekdays.
In any event, if you come to think of it, the Kidush wine is also drunk before the meal, in which there is not much difference between them.