On Saturday night, Oct. 4, Eva Gabor and her husband, Frank Jameson, will erect a tent over the tennis court of their Holmby Hills mansion in Los Angeles and stage a party for a delegation traveling under the auspices of the U.S. Air Force.

The Jamesons, as they did last year, will welcome to California the air attaches of 52 foreign embassies in Washington, ranging from Argentina to Zaire. Top Defense Department brass will be attending, while other DOD personnel will be escorting the foreign attaches.

Because Jameson is a consultant to and a director of several defense contractors, the party is raising some eyebrows in the military.

It is illegal for Defense Department personnel to accept social entertainment from any source that is engaged in or seeking business with the department unless the activity can be defined as part of a local civic or community relations program.

Jameson is giving the party, he said yesterday, in his official capacity ass honorary consul general of Jordan, a post to which he was named personally by King Hussein. It is a job which, Jameson says, takes a lot of his time. "We process 1,500 documents here a month," he says.

The West Coast consuls general of all 52 countries involved in the Air Force junket have also been invited.

So have a lot of big Hollywood names, including the Kirk Douglases, the Eddie Alberts, Lucille Ball and her husband, Gary Morton, the Lloyd Bridges, the Tony Martins, the Ricardo Montalbans, Aaron Spelling, the Robert Sixes and writers Harold Robbins and Sidney Sheldon.

There will be a choral group and an orchestra and dancing after dinner, with all the Hollywood columnists, including Rona Barrett, expected to record the event.

The decor could have upped the cost of the festivities by thousands of dollars if Jameson weren't getting it all free from a member of his family.

The white tent will be festooned with proteas, the newest "in flower, which can cost anywhere from $3.50 up to $30 per blossom.

Proteas, the national flower of South Africa, looks something like a spiky, half-open artichoke. They are being grown now in California by Jamson's nephew, William Teague.

Jameson says he has supplied them to the White House for parties and to the Iranian Embassy here when his good friend, former ambassador Ardeshir Zahedi, was a leading party-giver.

Because he is "part Scotch," Jameson says, he has arranged to get more for his money by having another party on Sunday night for leading California Republicans, including Sen. Sam Hayakawa, Rep. Barry Goldwater Jr. and Lt. Gov. Mike Curb.

Jameson laughs at rumors that the parties will cost $28,000.

"The tent, from Abbey Rents, costs $9,200 and is the biggest expense," he says.

Besides, he points out, half the tab is being picked up by his buddy, Cloyce Tippett, a former Air Force officer who is married to heiress Liz Whitney.