This thread is all I managed to dig up when searching for some guidance on table top paints.
I know the table "(..) playing surface shall be uniformly dark coloured and matt, but with a white side line, 2cm wide, along each 2.74m edge and a white end line, 2cm wide, along each 1.525m edge."
Now I'm about to restore our tables. Dents and scratches to repair, mostly. I plan to fill up damaged areas with woodfiller, polish gently, and then either touch up the restored spots or paint the entire table.
My searches have borne little fruit. Apparently, a Stiga Touch-Up Paint "Pen" (not my quotes) exists; a single shop has it, and it's expensive and available in green and blue -- but there's green and green, and blue and blue, of course.
Some DIY forums write about using "alkyd, or chalkboard, paint for the surface" of BYO ping pong tables. I suspect chalkboard paint might just be too grippy, but then again, a matt varnish might solve that problem.
Alkyd paint might be the way to go. Experiences in this area, anybody?