Melt 4 tablespoons of the butter in a heavy skillet and sauté the ham slices about 3 minutes on each side. Remove the ham to a heated platter and keep warm.
Drain the tomatoes and dust them with the seasoned flour. Add more butter to the pan if necessary and fry the tomatoes 3 minutes on each side or until tender, sprinkling each side with a little sugar. Remove and drain on paper towels, then arrange on the platter with the ham.
While the tomatoes are cooking, make the gravy:Pour off all but 3 tablespoons of the cooking fat. Stir in the flour and cook, stirring, for 1 to 2 minutes. Slowly whisk in the milk. Stir constantly until thickened, about 4 to 5 minutes. Season with salt and pepper.
Pour the gravy over the ham and tomatoes and serve immediately.