In part six, "Song," of section thirty-six, "Food & Drink," of Endymion Wilkinson's Chinese History: A New Manual, Fifth Edition (2018) there is the following excerpt:
Sitting on chairs to eat from shared dishes (heshi 合食) at a table became the norm in the Song, replacing the old practice of sitting or kneeling on mats and eating from individual servings (fencan 分餐).
But it lacks an explanation.
Nowadays it is hard to imagine individual servings being eaten in a Chinese group setting. Why where individual servings replaced with shared dishes during the Song dynasty?