It's 2:35 in the afternoon as I write this. I'm just back from another lunch at another downtown restaurant. Tomorrow--and for many tomorrows--it might be time to convert to ye olde brown bag.

What has pushed me to the point of ham and cheese? Another contretemps with a waitress.

It began with the table itself. The hostess seated me in a gloomy patch at one corner of the dining room.

That might have been fine for lovers or gossips, but my luncheon companion was a book on presidential politics. That demands light. So without asking, I moved three tables east, underneath a pool of 100 watts or so.

"Sir, did the hostess seat you here?"

I looked up from the ruins of the Carter administration. "No, she didn't, but I thought it would be OK," I said. The place was three-quarters empty.

"I'll have to check to see if it's OK," she announced. Off she went. Back she came. "It's OK," she said, as she rewrote the numbers on the top line of the check, "but I wish you'd have checked with me first."

That was reasonable. "Sorry," I said. "I'll be a good boy from now on."

She smiled. We were back to even. For a few seconds.

"Would you care for a cocktail?"

"I'd like a light beer. Do you have any other kind of light beer beside Miller Lite?"

"I don't know," she said.

I waited for her to add " . . . But I'll ask."

I'm still waiting.

"Well, Miller Lite's OK," I finally said, not having all day to spend on nonverbal communication. I ordered a salad and a hamburger. She brought the Miller, then a basket of rolls and butter.

"Would you take the rolls away?" I asked.

This is a trick I've used for a long time, my self-control being what it is. But this day, it was a struggle.

"But they come with the meal," the waitress said.

"I'm sure they do," I said. "But I don't want them."

Tensions were mounting. She removed the rolls, casting her eyes at the ceiling as she did so. Usually, I can't read minds. But hers said loud and clear: "Why me, Lord?"

The salad came: Russian instead of the Italian I had ordered. I ate it. Who knew how long it would take to get a replacement?

The hamburger came: french fries instead of the baked potato I had ordered. I ate them. Who knew how long it would take . . . .

The check came: $6.67. I plopped eight ones on top of it and returned to Reagan's first year.

A couple of minutes later, my concentration was jarred by a plate being set down beside my left hand. A dollar bill, a quarter, a nickel and three pennies were sitting in it.

"All that change is for you," I said. "I gave you eight ones. Didn't you know I meant for you to keep the change?"

"You've had me confused since you sat down here," she replied. "I didn't know what you meant."

Say what you will about ham and cheese from home. At least it never asks questions about what you mean.