This craftsman listed a bunch of tools and wonders how flat the table on each should be and how to flatten them if they are beyond the tolerances.
Michael Dresdner: A lot has to do with what type of work you perform on tools and what your needs are. If the tool is not performing up to snuff and you have identified a non-flat table as the culprit, then take it apart and level or lap the surface. You can flatten a surface by rubbing it on lapping compound (available from any machine tool supplier, like Grainger, Enco, Travers, etc.) backed up by a known flat surface – such as a granite block or a piece of glass. But if your worry is founded in numbers rather than results, sleep easy. If it ain’t broke, don’t fix it.