In general, table knives are placed on the right side of the plate. You need to direct the cutting edge of the knife inwards towards the plate. However, speaking of a butter knife, you should place it in a butter plate, and the blade should point downwards and left. However, the placement also depends upon the formality of the event. A lot of people do many tweaks depending upon the type of event and guests. So, there is a general rule, but one can tweak it depending on the event.