With no chairs available, they had to sit on the floor.
Tips
history
From 《旧五代史·李茂贞传》: 当食造庖厨，往往席地而坐 — describing the unruly troops of a Five Dynasties general eating in the kitchen and flopping down on the ground. 席 originally meant the woven mat used as a seat — ancient Chinese sat on floor mats before the chair became common in the Song dynasty.
culture
Cultural echo: the character 席 (mat) lives on in 主席 (chairman, originally 'chief seat on the mat') and 出席 (to attend, 'to appear on the mat'). 席地而坐 preserves the pre-chair sitting posture.
