The absorption of vacant commercial space in Montgomery County was slightly higher in 1982 than the previous year, according to the Montgomery County Office of Economic Development's Winter 1983 Office Vacancy Survey.

The Bethesda/Chevy Chase area experienced the lowest vacancy rate among the county's major leasing markets, 3.3 percent.

Nearly 810,000 square feet of space was occupied in the county in 1982, compared with 790,000 square feet in 1981, the survey found. In 1982, office space accounted for 510,000 square feet of space and the research and development market accounted for 300,000 square feet.

Other recent developments in commercial realty in the Washington metropolitan area:

* The NorVa Small Engine Division of Richmond's R.B.I. Corp. has leased 15,000 square feet of space at the Wellington Associates office and warehouse complex on Wellington Road in Manassas. The NorVa division is a distributor of small engine and service parts. NorVa will initially employ 12 employes.

* Solarex Ventures Group has leased 5,600 square feet at the Avenel Business Park at 201 Perry Parkway in Gaithersburg for its new subsidiary, Solarex Aerospace Corp. Solarex Aerospace will provide photovoltaic cells for satellite and space vehicle manufacturing.

* Wider Opportunities for Women Inc. has leased 17,812 square feet at 1325 G St. NW. Wider Opportunities is a Washington-based, national, nonprofit employment resource group for women workers.