Thanks guys! I had dinner at the bar at Tabla last night. It was really good as usual. Had the beet salad, which was delicious and simple; great for those of us who love beets. Also had the tabla ravioli which was as delicious as ever. I must be on a poached egg kick because after the ravioli last night I went to Screen Door for breakfast and had the farm grits which are topped off with two poached eggs as well as country ham and melted cheese. The portion was huge and the price really small. I can't say it tasted authentically southern to me, the biscuit wasn't as buttery or dense as my grandma's used to be and they used provolone cheese on the grits, which I had never even heard of growing up in Louisiana. I think cheddar would have been a better choice. Great atmosphere though, I would definately try it again for dinner.
Sunday brunch at Simpatica (SE 9th & Ash/Pine) is always fabulous, also had a decent breakfast at J&M Cafe (around SE 7th and Ash) recently. Another good breakfast is at Genie's on the corner of SE 11th and Division...some of the best breakfast potatoes in town. At Simpatica, they even provide free newspapers you can borrow, and getting a seat for one at the communal table is usually easy. J&M and Genie's have 2-tops and are open Saturday as well as Sunday, Genie's has a full bar.
There is also Kenny and Zuke's at Ken's Place (SE Hawthorne, around 18th) a Saturday only Jewish deli. Breakfast/brunch/lunch items; a counter to sit at (or a small table); and handmade/homemade food by guys that really care about their products. Kenny and Zuke's closes at 2:30pm and at 5:50pm Ken's Place serves their regular dinner menu, making this a dinner option as well.
For dinner Tabla (SE 28th a couple blocks south of Glisan and north of Burnside) has a nice kitchen-side bar top and a bar up front you can sit and dine at...I think the kitchen-side eating would be a fun thing. There are also small tables. Good food, great value (they have a 3-course $24 deal) - the ravioli is a favorite dish of mine there.
Cafe Castagna (SE Hawthorne near 17th) has plenty of small tables, inside and out and also a bar you can eat at. I really like the food here, the menu changes often and the burger is one of the best in the city. Good mixed drinks and good service here. Next door is Castagna, a more fancy and expensive restaurant, but also very good (and I think underrated).
If you are in the mood for sushi, Murata (200 SW Market) has some of the best in town, along with other interesting menu items. You can sit at the sushi bar or at a small table.
Also at 200 SW Market is Carafe. Good, solid, French bistro fare. Lots of smaller tables and very good service. There is free parking at 200 SW Market when you dine at either Murata or Carafe.
southpark, downtown (SE Salmon and Park) might be a good choice. Haven't been there in a few years, but reports have been decent. They have a bunch of small tables and a bar you can eat at. Keep meaning to get there and try the chocolate crostata with coconut sorbet/ice cream several folks have raved about.
Carlyle is a favorite of mine, and the bar area has a few small tables and seating at the bar. You can order off the regular menu in the bar as well as off the bar menu (which features a stellar burger and fries). IMO, it is worth going out of your way (out of downtown or close-in SE) as it is at NW 17th and Thurman.
Though I have never had a meal I have enjoyed there, lots of folks love Park Kitchen, just out of the range of downtown on the NW Park Blocks around Flanders/Glisan, I think).
Happy solo dining!
I really like the Red Star Tavern on SW 5th and Alder/ at the 5th Avenue Suites Hotel.
They serve great breakfasts and dinner is good. In the bar area, are small booths where a single diner can sit and feel comfortable and also watch the entire bar and room, so it can be entertaining. They take very good care of you too.
I like Mothers on SW Stark @ 2nd for breakfast
Another nice dinner could be Typhoon at the Hotel Lucia on SW Broadway & SW Washington. They have small tables for single diners in the front room as well as a bar..
These are the close-in downtown places I can think of..the Pearl is full of good restaurants that are comfortable for single diners.