These clamps from BuildPro are perfect for use on tables with 5/8" or 16 mm holes. 

While originally designed for 5/8" holes, the difference in size between 5/8 and 16 mm is only 0.005" (less than two Post-It Notes thickness). Our tests indicate equal performance of pressure exerted with these clamps when used with 5/8" holes on thick plate vs 16 mm holes on 1/4" plate without slipping. 

One caveat for users of 1/4" thick tables:  If you are using the larger clamps (8.5" UEN5200) and you crank down beyond max pressure you might create a raised ridge around the hole due to deformation of the table surface.  This is because all table mounted clamps operate through the principal of binding against the edge of the holes.