Set a couple of kitchen glasses loaded with flowers into the box, and place pillar candles between the glasses. Arrange the flowers so they are away from candle flames, not over them.
Finish the box with a length of grapevine wrapped around the outside. Tack it into place with tiny finishing nails, if necessary.
Replace flowers as they wilt and you'll have a long-lasting arrangement for your table.
TIP: Remember to never leave candles unattended.