How are you running pinmame? Are you using mamewah, VPL (Visual Pinball launcher) or something else?
On my PC I use VPL which auto scans and loads your tables in a windoze format.
To run Visual Pinmame, you need to first install Visual Pinball. Then create a directory inside of the main VP folder called "vpinmame."
Then install Visual Pinmame inside that directory.
Install your tables in the "vpinmame" tables directory (Unzipped) and install your table roms in the "roms" directory (leave them zipped). Move any .NV files to the "nvram" folder in "vpinmame."
And it should work just fine.

As far as Mamewah... that's a bit harder to set up. I have a friend who's done so, but on a 25" standard res arcadce monitor the tables are a bit... fuzzy.
The expensive thing to do would be to run them on a VGA compatible arcade monitor. Slightly less expensive would be to run them on a large size PC monitor.
It really depends on the cabinet you're installing it into. If you're building a standard arcade cabinet, you have lots of options for monitors. If you're perhaps building a pinball cabinet mockup, you're limited on what kind of monitor you can use due to space limitations. In that situation you'd almost want to use a flat panel monitor that you could lay on the "playfield" of the cabinet.
Rook