I believe "Under the table" in this case means the management was unaware and customer was not billed. It's the only scenario I can think of that would in this

I believe "Under the table" in this case means the management was unaware and customer was not billed. It's the only scenario I can think of that would in this context be on the positive side of most ethical frameworks. Happens a lot, in many types of companies and policies, that helping the customer has to be "under the table" / "off the books" :-/