A school box.
I hate the terminology but it has stuck over the years. Each child has a box in their rooms in which we keep notebooks, artwork, file folders, current portfolio. Makes it easy at homeschool registration time.
Most of the time, in our years of homeschooling, we have kept these boxes in bedrooms - away from prying hands of little ones. And while we don't have little ones now, the principle is the same - the boxes with "proof of learning" for the state stay away from the hands of our visiting little ones.