There are now quite a few of these type of books around, but this volume and its partner (the one about Does Anything Eat Wasps?) are the originals. And they are very entertaining!
The information is taken from New Scientist magazine, however, so very often it is quite complex and detailed. The questions are very varied, and range across natural history, biology, chemistry, physics, astrophysics -- you name it. Sometimes the questions are very basic; sometimes they are complicated -- and sometimes the answers can be half a dozen lines or several pages long.
These trivia snippets are a bit like grown-up factoids: interesting to read and file away, and maybe useful once in a blue moon, but mainly worth reading to satisfy some curiosity.
Because the book is divided into sections, and each question forms a different topic, it is very easy to dip in and out of this book. It's much harder to read it all in great long sessions, as you would a novel.
So this is maybe a book to keep in the small room and flick through when the mood takes you!
Although it is non-fiction, Penguin's Feet isn't a reference book as such. Because the topics are so different, and the replies vary in depth and detail, this really isn't a serious science guide.
Instead it's a jolly compilation which lets you surf through some science -- and it's no problem if you skip the bits you don't understand!