The two angled ports are the line power (red/black) the L shaped prong is for the neutral conductor ( it is basically an old dryer outlet of the non-grounded type) The grounding style 30a 240v outlet has 4 prongs with tiny letters next to each hold down screw G=ground W=white x=(red or black) y=(red or black) The new construction code will require that the outlet you put in is grounded in order to pass inspection. Your table saw will need an adapter or a new plug on the end of the cord. I looked around on the net to find the NEMA outlet configuration for you, but right now I have yet to find it.
