Went here after reading the reviews on Trip Advisor - so glad we did!! There was 5 of us that went, and we luckily booked a table before hand. We arrived at 6pm and sat down straight away with some bread. Don't know why one of the previous reviewers slated the "old tablet device" - it told you what you needed to know, it wasn't an iPad but it worked!!
We ordered an "Edible Crab" (Its actually listed on the menu as this) and shared that between 2 people, which the waiter, who didn't really speak English, pointed out that it was enough for 2 - the other people ordered the Prawns in Garlic (which came out sizzling and smelt lovely) and the last person had the Giant Tiger Prawns - he had to wait a little while for those, but it was well worth the wait.
The restaurant itself is very busy and well run for a slightly smaller sized restaurant - overall was a good experience and we were very glad we went - although, I wouldn't recommend this to anyone who doesn't really like fish, as this is pretty much all they sell, apart from a Steak Sandwich, which is the only variant on the menu.
Would definetly recommend this to anyone going to Lisbon! Oh and the manager is very helpful, grabbed 2 taxi's for us when we asked if he could tell us where the nearest taxi rank was.