I’m a regular visitor to a weekly production planning meeting without tables. The meeting is an hour long, so participants are seated in chairs facing a screen and wall, in front of which different people lead parts of the meeting.
The other day I was in a planning session several hours long. People had chairs but the only tables in the room were for project drawings and food.
My observation is that people are more engaged in these meetings than they are otherwise. The tables provide a barrier behind which people easily retreat. In the weekly production meeting you can observe that people are closer together, willing to speak more readily and are more focused on others as they speak. In the planning session people spent more time standing and focusing on the planning board than I usually observe.
Bottom line, if your meeting is longer than 20 minutes you may want to keep the chairs, but try ditching the tables and see if it makes a difference.