Small may be beautiful, but big is what parties are in May and June.

In the wake of azaleas and dogwood come graduations, weddings, golden anniversaries -- celebrations where the dimensions of the invited, even standing close together in the very friendliest fashion, exceed the dimensions of the largest room in your house.

And so you must search for outer space.

There are the standard reception rooms in hotels and restaurants. And churches and even schools have been known to provide halls that don't make the celebrants feel compelled to line up and address everyone as sir or ma'am

If you are a corporate associate of The National Trust for Historic Preservation, or a nonprofit educational group with a 501c3 status (it is like measles; if you have it, you know it) you can apply for use of the elegant Decatur House or the Woodrow Wilson House.

The same qualifications (though this time you must be a corporate member of, respectively, the American Institute of Architects or the Corcoran Gallery) will give you access to the Octagon House, built in 1799-1800 and furnished, on the first floor at least, in period pieces, or to the Corcoran.

Also elegant, but open to the less lofty, is Anchorage House (603-605 Queen St., Alexandria, 633-3705), a Georgian mansion furnished in antiques and with a garden to wander through. It can handle receptions of up to 200, and sit-down dinners for 60. Use of the house for three hours, with food and nonalcoholic beverages, costs about $15.35 per person, based on a group of 100.

Would you feel too much like Nora if you had your wedding reception in the Doll's House and Toy Museum? Well then, perhaps a gentle afternoon tea. The museum (5236 44th St. NW) is one block south of Western Avenue and one block west of Wisconsin. It has long been known for its children's birthday parties, but it also can be rented by adults, at rates which vary according to how much space and what kind of party you'd like to arrange. Call Mrs. Jacobs, 244-0024 or 244-0082, for details. y

To impress young graduates, invite them to mingle with the presidents at the Wax Museum (4th and E Sts. NW, 554-2600). The museum can handle up to 300 for rates which vary according to what you want.

If you'd like an arty party, The Washington Project for the Arts (1227 G St. NW, 347-8304) is available for an evening. No smoking (because of Fire Department regulations) and a maximum of 200 people. Rates vary according to what the party is for.

The nearby D.C. Space (7th and E Sts. NW, 347-4960) holds between 100 and 150 people and can be rented for $25 an evening (or 10 percent of the admission if you're planning an entertainment). They are booked far in advance, so plan ahead.

Many art galleries, like the Miya at 720 11th St. NW (347-6076), will occasionally agree to rent space, depending on what it's to be used for.

That, in fact, is often true of large and unlikely places, so it would not hurt to inquire of any space that takes your fancy if it would like to be full of your friends.