If you lose your umbrella for instance, that would be tappa. But you're not likely to 'lose' a plate in that sense. Hints are just hints, not all hints work everywhere.
Hello, would you consider "I am about to" an alternative acceptable version to "I am going to" in this situation?
I love the 'kommer att'. Reminds me of a Southern USA way of speaking of the future. As in: I'm thinking of fixing to get ready to make dinner. Wonder how that would work in Swedish?
I guessed "you might drop the plate" could be a good translation here. Is it wrong that I was marked wrong or was my translation not good enough?
It was not a good translation. For expressing "might" like that, it's common in Swedish to use "kan", "kan komma att" or "skulle kunna".