In the 17th-19th centuries, prior to widespread use of electricity, candles provided the main source of household lighting. The wicks did not self-incinerate as ours do today. Thus they needed careful trimming, even while lit, to maintain even light and to prevent excess smoking. A metal candlesnuffer could be used to trim the wick without extinguishing the flame, and the scoop would catch the burned wick. It was common to also include a snuffer on the same tool so that the candle could be extinguished safely without spattering liquid tallow. You can think of this as an early multi-tool!