I’m quite surpised that no one has a clue.
A shulchan is a ” mini-mazbeach.”
The meals we eat and the brachot we say are like offerings on the mizbeach.
Don’t feel too bad, I once had a similar experience when I was a rather young mother, I put one of the children I was holding on the table and a guest, who happened to be a very assimilated Jew mentioned to me that he was surprised to see that I, a religious Jew, would show such disregard.
I quickly, took the kid off the table and was even more embarrassed because of the source of the criticism.
I have not forgotten, to this day, the lesson.
Be thankful that the source of criticism was from someone who wants to help you grow and not from a source that for whom it is a source of derision.
Good Luck with your essay.