What you seem to be saying is that you want a sort of "electronic" catalogue, so you can select what the customer wants, punch them up on the screen, and Mach goes ahead and does them.
This is certainly possible (and not too difficult), but there are several parameters that need to be considered, for instance, it would help if all the signs were the same size (not absolutely necessary), or even more importantly, the position of the three boards you are able to put on the table is fixed - i.e. the start point of each board is fixed. This means that you would have three starting positions, identifiable to the machine. (If the boards are 4" x 1" can you only get 3 on - what size is the table - you say it is 3 ft long - is it only 12 " deep) (If you only use 4 x 1, the positiong could be just a matter of a top or bottom fence, then the boards (as many as your machine can cut at one go) just clamped together - Mach could work out the relevant positions of the boards)
The starting point(s) can be defined in the "fixtures" table - say g56, g57 and g58.
I would lean towards catalogging your "signs" perhaps in a macro form - say m301, m302, m303 etc through to your last sign - and as Hood says, take out the M30 at the end of each. You should also include a "do nothing" sign, where a customer unfortunately only wants one or two signs. I say a Macro because these are stored and recalled by single number commands - e.g. M301. They are not as convenient in that they do not display correctly on the tool display, but if you are not watching the machine, then it doesn't matter.
You could store them as seperate files and recall each as you would a computer file - but it seems to me the macro is the simpler.
I would customize a page (or construct a new one) with the three DRO's for the three signs and a start button.You could have all the signs available displayed on the page ( or all the numbers with a one line explanation ) and if you wanted to go really efficient, you could click the number and give a preview of what the customer was getting. Depending or your programming, you could either click the "sign number" to enter it, or type it in the relevant DRO.
The program on the start button would run
a) any start up procedure you use,
b) any homing /positioning you use - and this would be necessary so the machine could fix the position of the start points
c) pick up the offset - e.g. G56 from the offset table, and then the first macro from the DROs - run it.
d) pick up the second offset from the table - and the second DRO macro number - run it
e) pick up the third offset and the third macro number - run it.
f) if the "do nothing" macro number is is any of the DRO's the machine just moves to the next one.
g) the machine ends by moving the cutter well out of the way so you can "unload" and you could even include a finishing bell or similar linked perhaps to the coolant relay pin and accessed by M7 or whatever. The "do nothing" number could be entered in each DRO ready for the next run.
h) you could include little "helper" buttons, like "repeat" etc
Your operating procedure would be to bring up the screen, enter the DRO's, put in three boards to cut, and press the start button - I can't think how you could improve on that -