All the smaller rotary tables are inherently short of space to accommodate work holding clamps. In my view the 8″ – 200 mm size being the smallest that can satisfactorily exploit the common import Tee nut, stud and step block sets without too much futzing around. Even then it’s all pretty tight.
Best answer is a grid of tapped holes plate semipermanently fitted to the rotary table. I reckon 5 spot dice pattern on 1″ – 25 mm centres with 1/4″ or M6 threads works pretty well for most things. If you do predominantly very small work consider a tighter spacing with M4 or M5 threads. The optical lab equipment companies make aluminium breadboards with this sort of hole pattern that aren’t completely unaffordable if you don’t fancy tapping all those holes for example Thor labs:-
https://www.thorlabs.com/navigation.cfm?guide_id=45
is the index page for theirs. Other firms do similar things. Or maybe half the price from AliExpress.
For small work very simple sheet metal, 3 or 4 mm is plenty thick enough, bent L shape clamps with a slot or choice of bolt holes to take the fixing stud or screw work pretty well. Easy DIY and no tears lost if you cut into, or even through, one. Thicker, more engineered ones can have jack screw, with a foot so it doesn’t chew the table surface, can cover a greater range. On my little BCA I found a knurled knob on the jack screw, rather than a proper hex or allen socket, generated perfectly adequate clamping forces for small stuff and small cutters.
Clive