Before eating, you should break the bread into moderate sized pieces with your fingers. Then you can butter the bread one piece at a time. There were some differing opinions on whether you should hold the piece of bread when buttering or hold it against your plate, not in your hand. The most prevailing opinions said to hold the bread in your fingers. Toast and hot biscuit halves can be buttered all at once since they taste the best when the butter is melted.
When butter is served as individually wrapped squares, leave the empty wrappers on your bread plate or tucked under the edge of your dinner plate if you don't have a bread plate.