Trim fat from ham slices, leaving 1/4 inch fat remaining. Score fat at 1-inch intervals to prevent curling.
Preheat electric skillet to low (225°); place first ham slice in skillet, fat side of ham near edge of pan.
Place second slice on top of first, with fat side of ham near opposite edge of pan.
Stack remaining ham slices overlapping each slice so fat side is near edge of pan.
Cover skillet, and cook over low heat 15 minutes. Remove ham slices from skillet. Turn over each slice, and return slices to skillet, repeating stacking procedure.
Cover and continue cooking an additional 10 minutes.