Washington-area grocery-store food prices rose 0.5 percent in October, reflecting increases in the prices of cereal and bakery products, dairy products, fruits and vegetables, the Bureau of Labor statistics said yesterday.

October price increases in those categories more than offset declines in the costs of meats, poultry, fish and eggs. In particular, prices rose for items such as carbonated drinks, most processed vegetables and bakery products, the bureau said. On the other hand, prices for beef, pork, fish and eggs all dropped.

The monthly increase followed a 0.2 percent decline in local food prices in September, when the prices of cereal, bakery and dairy products all dropped.

Local grocery-store food prices rose 2.5 percent over the last 12 months, compared with a 0.6 percent increase nationally.

A spokesman for the bureau could not explain the difference, but noted that it may reflect a number of factors, such as local consumption patterns, retailing practices and the fact that the small local sample is subject to substantially more measurement error than the national figures.

Local prices rose 1.6 percent for fruits and vegetables, 1.2 percent for cereal and bakery products, and 0.8 percent for dairy products. The biggest price increase was in the general category of "other" foods, which were 2 percent higher. Prices dropped 1.8 percent for meats, poultry, fish and eggs.

The index of local prices for "food consumed at home," or store-bought food, reached 321.1 in October, which means that Washington-area shoppers would have had to spend $32.11 last month for a basket of food that cost $10 in 1967.