I'm not sure what use this (No. 640) shape of lidded pot had. There's no spoon slot, but there is a ventilation hole. It came from eBay this week and when it arrived I was surprised that it seems to be stoneware.
The Stripy Picotee glaze patterns were introduced in 1932, the pot dates from about that time and this particular arrangement of coloured stripes is number 40. I know I should have made the camera focus better, but in real life the stripe are very blurry too.