ell in the first row with a value other than 'auto' for the 'width' property determines the width for that column. (...)
    Any remaining columns equally divide the remaining horizontal table space (minus borders or cell spacing).
  "
  Section 17.5.2.1 Fixed table layout
  http://www.w3.org/TR/CSS21/tables.html#fixed-table-layout


  Middle column width calculations
  --------------------------------

   30px : half of border-left since such border must be split with cell in 1st column
 +
   80px : width 