Why where individual servings replaced with shared dishes during the Song dynasty?

Question

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?

Answer 1

The answer seems to be included in your question. Rongguang Zhao explains in "A History of Food Culture in China" (p.18):

Put another way, eating habits shifted from sitting alone on mats to sitting on chairs around a table. This made using shared dishes practical. And after coexisting for a while with individual dishes, shared dishes eventually became the norm.

(This arguably doesn't answer a related question, namely why they decided to move to sitting around a table to begin with. For added comfort or because it became more affordable to do so, perhaps?)