An 8th century peasant probably wouldn’t immediately call you a witch, and even if they did, they probably wouldn’t execute you for it, so long as nothing suspicious happens afterwards. So long as you don’t literally show up in your Time Machine in the middle of the day directly in front of them, you’ll be fine. Keep a low profile and people will write a lot of things off as exotic goods. You could just say these are a candy from somewhere far away and they would have no way of knowing.

See: https://www.youtube.com/watch?v=-aSdFrPnlRg