I seem to have a fairly large chip in one of my foundation cinderblocks.
Is this type of damage repairable as a DIY project?
This doesn't look like foundation damage. This is a settling of the pathway around your house. Good news is that it doesn't look like serious problem, at least from what I can see from the picture. This issue should be fixed because it will only get worse, and then rain water will go under you foundation and that could be a problem. You should demolish pathway preferably all of it, if not than at least parts that have sunk. Then, pour some gravel and compact it. Over this layer you can pour concrete, of course use reinforcement meshes, so the new pathway wouldn't crack. Also, I like to divide these paths every 2-3 meters with a piece of wood or even better with Styrofoam which I take out after concrete has hardened. These way pathways can "breath”. I forgot to mention that it should be under slope so that water would go from the house.