Have been buying Lonely Planet guides for years, and we all know that the quality of the maps is far from decent, especially in this kind of weekend away mini travel guide. But in this case I must say that on top of the quality of the map, the information was inaccurate. Come on LP, spend a bit more time and efforts on decent maps! Also, I am not quite sure what "food in a budget" is anymore! Went to a few of the recommended places listed as such, and the bill came to 20 euros per person in most of them, without starter. ALthough not expensive, I would not list it as budget at all! Also, we had an awful experience (food, staff, price) at some of the most recommended portuguese restaurants (Cervejaria Trindade), so ignore all the notes on that place and save your money. Also, by reading the book you may think that Lisbon is quite dodgy in some areas, which we entirely disagree with...probably just as any other major european city you gotta be cautious in the usual situations (nightime etc). OPening times for some places were also inaccurate.
Overall, you would be better off not buying this kind of guide, doing some research online in forums etc and acquiring a map once in Lisbon. Frommer's guide was similar, although their maps are always better than LP's.