Just drill out a square of metal, take some wooden pegs, put em together and park a car on it?
Good lord! And after doing a couple of hundreds, all that back and forth would really stress your clutch 
Howz about 10 at a time? What exact force are we talking about (ft/lbs)?
Well, a bit more serious now, as I'm figuring it out, I (we) have some facts to start from, like that old Argox post on tablet pressing in ultra full detail. It even has formulas for getting the exact force you might need to press an XXmg tablet.
BUT, if you like to go a little more "empiric" you can check the specifications from LITTLE lab presses, those single stage (nevertheless hydraulic) presses, you know. Well, they use a compression and PRE compression system. We can forget about the pre-compression, at least at the beginning. Always start simple, you'll have time to mess things up later . So, we can see that things that they are able to press UP TO 11mm diam. pills, with a 10ton pressure, they have a max. depth charge of 17mm, etc.... Let's put 10mm for our sake and make math easier. Now that´s a whole damn pressure being applied. BUT, if you make it 10 at a time...well, math is easy. They say you can very well press nice pills with 1ton. Who knows? I don't 
Still, a 100mm pill would be a damn flying saucer! Ok, you can engrave almost anything there, still... I'd rather go for an 8mm standard. Now if you redo the math you get a little bit more "force"/hole.
I've been thinking about a "9 AAT" (at-a-time, yes, a new acronym) where any hole could be left unused (without affecting the rest) if found out that the kg/mm2 were not enough. Pressure is applied via a cam(shatf? still don't know about it, but cams surely) wich is moved by a modified hydraulic car jack ($50 at a repair store)
Also, I have very (VERY) raw sketches about a feeding system for a single press. Cause I'm trying to figure out both, a "various at a time" and a single press (here would work the feeding system). So far, if I can make something satisfactory with it, I'm pretty sure a single one would be better than a multiple set up, due to faster loading and expulsion.
Chemically enhanced.
