This was heard at an administrative hearing. The speaker was talking about work that he was currently performing. It is a congruent conflation of “off the books” and “under the table”, both meaning to do something in secret so that taxes won’t be paid. Then again, maybe the speaker works in the basement of a library. A follow up question hopefully was made. A big thanks to John Costello for hearing this one.
If you liked this one, check out my book on malaphors, “He Smokes Like a Fish and other Malaphors”, available underneath on Amazon. https://www.amazon.com/dp/0692652205