I made a small X Y table, but with iron because I can't find wood robust enough to assure a decent precision. Sorry, I don't have drawings... I'll take some photos, anyway.
Basically it is made with a 2 mm iron sheet.
the Y axis movement is obtained with two L shaped bars welded below the sheet, sliding on the sides of the drill table.
The X axis moves on a sort of T rails created just stacking two layers of flat bars over the sheet. Inside these rails there are sliding flats, same thickness of the central layer, with recessed bolts for a small drill press vise.
I made it because my drill press don't have a lot of clearance, and a commercial X Y vise would reduce the available space too much (apart to be more expensive than the drill itself).
X and Y axes are surely not perpendicular, but for what I'm doing now it is better than a plain vise bolted to the table.
A rotary table is in my thoughts: I think to bolt a bearing inside a thick piece of MDF to the central hole of the table, adding some rails to have a sort of vise working as a 4 jaws lathe chuck.