If you are willing to pay the performance penalty (if there is one) then you can make a custom column with the sizes of all formats. The column type should be "Column built from other columns", without "behaves like tags". The template for the column is
Code:
{:'formats_sizes()'}
The possible performance problem arises because the GUI must go to the actual file system to get the book file sizes.
The column contents will look something like this.