My best recommendation would be to use a combo of the knife tool and the replicator.
You'll want the knife plugin from here versus the built-in knife, as this version of the knife will work with as a plane:
http://supercoldmilk.com/ac3dplug/knife.html
Create a rectangle that is larger than the outer dimensions shape you want to slice. Highlight it, then from the Tools menu select Replicator. Set your number of copies and the distance apart in the Translation field. This will be your slices. Then click go.
AC3D should make a whole stack of rectangles. Click the knife option on the tools menu. Select one of the rectangles and click Set Knife. Make sure "Slice surfaces" and "Delete Knife" are checked. Then, highlight the object you want to cut and click Slice. Repeat this for each slice, and you'll have the object evenly sliced up.