Did the wealthy use Trenchers? It seems like that would be very unlikely, except maybe in earlier periods.
Sure did! They might be made out of pewter, or silver, or nicely crafted wood. Table-manners and how the food was served was a bit different than today.
For instance, for the wealthier classes, it was common for the food to be brought in and served to groups of four people at the table, who would cut small bite-sized pieces off of the meats/breads/cheeses, to place on their trencher, and they would eat it from there in small quantities. The idea of putting an entire meal on a plate for one person would have been seen as extremely bad taste and gluttonous.
They would also only touch the food with the thumb and first two fingers from their right hand to eat it, and stabilize it with the same fingers of the left hand while cutting servings. This way the hand that touches your mouth never touches the group servings. Also, the three-fingers set them aside from the peasantry, who would eat using all five.