Butter plate : locut. In several metaphors born from the fifteenth century, the butter is a symbol of wealth, an emblem of Luxury.
One can well imagine then, around a banquet or a reception with people of high society, that the guests who had the most enviable positions or giving the most power, were pampered by the hostess and that the most buttery dishes on their plate. It is from these small favors offered to the powerful that our metaphor could have been born, butter being the symbol of the various things which they can benefit from thanks to their status, whether in the form of gifts or of profits obtained in more ways. or less lawful. But we cannot ignore the possible influence of a play on words on another meaning of the word. plate, that related to tax. However, from the moment when the collection of this tax was entrusted to executors of not always exemplary probity, it was easy for some of them to tamper with the figures and to appropriate part of what they harvested, these partially diverted sums giving them the wealth necessary to claim to be part of the butter-consuming caste.
See Butter dish.