What kind of Christmas pudding was that?

Sort of right, Strntz, but that was much longer ago, around the fifteenth century; it was then called 'frumenty'. The meat element gradually disappeared as more fruits and sweet-stuff was added. The pudding the Cratchitts are eating is just that, a pudding, or 'dessert' as restaurants insist on calling it. Mrs Beeton has a recipe for it in her cookery book, published in 1861.

CHRISTMAS PLUM PUDDING (Very Good)
INGREDIENTS.— 1–1/2 lb. of raisins, 1/2 lb. of currants, 1/2 lb. of mixed peel, 3/4 lb. of bread crumbs, 3/4 lb. of suet, 8 eggs, 1 wineglassful of brandy.
Mode .— Stone and cut the raisins in halves, but do not chop them; wash, pick, and dry the currants, and mince the suet finely; cut the candied peel into thin slices, and grate down the bread into fine crumbs. When all these dry ingredients are prepared, mix them well together; then moisten the mixture with the eggs, which should be well beaten, and the brandy; stir well, that everything may be very thoroughly blended, and press the pudding into a buttered mould; tie it down tightly with a floured cloth, and boil for 5 or 6 hours. It may be boiled in a cloth without a mould, and will require the same time allowed for cooking. As Christmas puddings are usually made a few days before they are required for table, when the pudding is taken out of the pot, hang it up immediately, and put a plate or saucer underneath to catch the water that may drain from it. The day it is to be eaten, plunge it into boiling water, and keep it boiling for at least 2 hours; then turn it out of the mould, and serve with brandy-sauce. On Christmas-day a sprig of holly is usually placed in the middle of the pudding, and about a wineglassful of brandy poured round it, which, at the moment of serving, is lighted, and the pudding thus brought to table encircled in flame.

This is pretty well the same recipe we use today. Us non-meat-eaters have to make sure the suet is vegetable, not beef.