I'm surprised how many are shocked at those numbers. Out here, that is the norm. It really isn't a big deal for me to hear a number that size. Of course, we don't tend to have the formal, sit down, dinner-type receptions. We have dessert and finger foods, and many receptions are held at church halls or gardens. Guests come and go, only the closest friends and family tend to stick around for the whole thing. Others just come sometime during a 2-3 hour span. Greet the newlyweds and their families, eat, visit with others, and leave. Some might have dancing, but many don't. It all balances out fine.
I'm doing that with my reception, and our numbers are disproportionate because he isn't from here, but in the UK we are having a second reception that will only have 20-30 guests. It will be a sit-down dinner at a hotel and more formal. I only have two guests at that one--Dad and his wife.