This is a book named 'Poirot Investigates' written by Agatha Christie. It has a collection of eleven short stories. All the mysteries in this collection are solved by Hercule Poirot. He is a fictional Belgian detective created by Agatha Christie.
Poirot became the first fictional character to be covered on the front page of The New York Times when his obituary was printed there on 6 August 1975. This book contains the below stories :

The Adventure of “The Western Star”
The Tragedy at Marsdon Manor
The Adventure of the Cheap Flat
The Mystery of Hunter’s Lodge
The Million Dollar Bond Robbery
The Adventure of the Egyptian Tomb
Jewel Robbery at the Grand Metropolitan
The Kidnapped Prime Minister
The Disappearance of Mr. Davenheim
The Adventure of the Italian Nobleman
The Case of the Missing Will