Slats, you will support the work piece on slats. Think how you will support your slats. If they have to flex a bit to fit they are more likely to behave themselves.

If it is a small piece of metal you will need the slats close together with more support from below. If it is a large sheet the slats can be further apart. Why not put slats close together in one corner and further apart over the rest of the table?
The other slat function is the tilt. You cut a complete part and instead of resting flat on two slats or falling through it tilts and jambs itself at an angle. The tool slams in to it on a rapid transit and does hideous damage to itself. You would need vast numbers of slats to avoid this but it is quite predictable. You can put a bumper ring around the tool tip to spot them and apply the brakes.