(do something) at the dinner table
You can talk this way about things that a person does while eating dinner at home:
My wife and I made a rule not to talk about work at the dinner table.
How many times do I have to tell you? No cell phones at the dinner table!
Of course, for most people the "dinner table" is the same table that they use for breakfast and lunch. At breakfast, you can call it "the breakfast table":
I used to rush and do my homework at the breakfast table in the morning.