Currently, when you change cell, the only info the table gives is current size, 24h growth, and available. Per nkem, available means the number of cubes available to you to color.
However, the cells we know are completed (e.g. IFLS neuron) have an availability number approximately equal to the current size, which gives no clue that the cell is actually completed. A % completed column (or some graphical overlay) would be nice to show people which cells really need work done on them.