I actually have that book sitting around, I think I got it as a gift. They list the steeping grains but then in the little box tell you how much additional base grain to add for the partial mash, giving around 4 lb total per recipe which is more like it. Most of the recipes have at least a 1/2 lb total of steeping grains but I see what you mean, sometimes they call for only 1-2 oz of a given grain. This being a clone book some of that seems to be color adjustment, for example when they call for 1 oz of a darkly roasted grain. Then some of the recipes call for a strongly flavored grain like aromatic or honey malt, which may explain the small amounts.
Edit: One thing, as I look through that book some more I see the instructions aren't great. For everything including the lagers they say pitch when temp under 80 degrees, ferment 5-7 days, transfer to secondary "until fermentation is complete". They've also got some sour beers in there but don't say anything about technique. I'd just be careful which ones you pick to brew and follow some better directions.