None of these are really close but not a far walk:
There is a great inexpensive diner on Lex and 40th called Scotty's Diner.
Just down Lex @ 29th is Penelope which is fabulous and a bit more creative.
Ess-A-Bagel on 3rd Ave & 51
There is also a decent diner on 2nd Ave & 38 Townhouse Cafe the sign says "Best food in town"
I actually do not get out to that area much, but I believe there is a Le Pain Quotidien near you, on 3rd ave and 44th st. It's not fancy and it you can sit and read for as long as you like. I love their soft boiled eggs and their jams. They have several locations in Manhattan.
There's another PQ on 2nd Ave & 50th St.
Places I either haven't been, or not lately, but which might be worth trying: