Looking at the chart, it appears to me to be poorly drawn. The 10 DME point appears to be on the 3 degree profile at 2500 feet.
Anyone else see the potential for starting descent at 10 miles instead of 8?
I think you're misinterpreting the chart.
At 10 DME the DME steps allow for a minimum altitude of 2500' AMSL, which provides terrain/obstacle clearance. However, to be on the 3 degree constant descent approach slope, one would be just a touch over 3000' (Descent from 3000' commencing at 9.6 DME according to Jeppesen Plate 13-2 eff 26Aug10).
The chart at Appendix D doesn't appear to be a Jeppesen chart. Whilst it doesn't give crossing altitudes for all DME, it does give enough for the approach, in my view. I'm not sure what would trigger "starting descent at 10 miles instead of 8".