1. How would you know?
2. The Last Supper was not "around a table," if you mean the way we do it. The Lord and the Apostles were reclining, and all gathered on the outside of a u-shaped arrangement of three tables. Given the customs of where the "host" would sit -- if that was Jesus -- then indeed, he and a good number of the Apostles were facing the same way as he was; they were not facing him across the table. So that doesn't help you.
3. Archaeological and documentary evidence from Roman "house churches" is against you. See: http://blog.adw.org/2014/08/the-ancient-mass-in-the-house-churches-was-not-as-informal-as-many-think/