The subtotals are the 499 standard subtotals you set-up in Data Files. Every item you take off adds to the subtotals specified for that item's units in the Databook. (Units with no subtotal specified add to subtotal #499: EXPENDABLES.)
For each of the 499 subtotal descriptions the Bid Summary shows separate material and labor amounts. You can also set-up a "miscellaneous" amount for each subtotal. You might use this to include additional monies for quotes, etc. You can change any of these amounts and apply a lump sum or percentage adjustment to it.
The Bid Summary also sums all of the adjusted material, adjusted labor, and adjusted miscellaneous amounts into overall material, labor, and miscellaneous subtotals.
For more information, see Subtotals.