No, this is not a real Sinatra error :).
This is the personal homepage of Elad Meidar, a web developer and an entrepreneur specializing in Ruby on Rails. I hang around in Israel, and i am currently having the best time of my life over at Fiverr.com
I am a proud member of RailsBridge, Helping new Rails developers get into our world and also contributed a few Patches to the Ruby on Rails core.
Tables became the scape got of bad design practices, many sites and programmers still relay on table based layout-ing to properly align and position elements on a web page.
The “standard HTML table tag”http://www.w3.org/TR/html4/struct/tables.html#h-11.2.1 can contain many useful and semantic sub tags that are not being used on many sites iv’e seen, even those who use the table tag for what’s it is actually made for. Tables.
You're seeing this error because I think it is funny.