The Laws of Shavuos / Milky Food

1. The custom is to eat milky food on Shavuos. The reason for this is to remember the two breads offered in the Temple on this festival, and we therefore eat both milky and meaty foods, so there are two types of food, and with each we eat a separate loaf. Another reason given is that immediately after we were commanded about the forbidden foods, we were unable to eat meaty foods, as they need much knowledge (checking the knife, porging etc.), and we therefore ate milky food, and we are remembering this. (Shulchan Aruch and Mishne Berurah 494)

2. Even on this day we must be very careful to keep all the laws appertaining to the separation between milky and meaty foods and the eating thereof, like in the rest of the year. (ibid)