As you know there a number of exam for the post of Food Inspector. So you must have a fine knowledge regarding the syllabus of the examination along with the question pattern of that exam.

So based on generalized exam syllabus I can suggest you the following books:

1) WBSSC Food Sub - Inspector : Recruitment Exam (English) 1st Edition
Author: Arihant Experts

2)A MODERN APPROACH TO VERBAL AND NON VERBAL REASONING (English) Re
Author: R. S. Aggarwal

3) Indian Polity (English) 4th Edition
Author: M Laxmikanth

4)General Mental Ability Logical Reasoning & Analytical Ability MCQs 1000+Q: Useful for IAS | PCS | NDA | SSC & all other examinations (English)
West Bengal SSC Food Sub-Inspector Recruitment Examination
by Dr. Lal (Author)

5) Current Affairs [AUTHOR: JAIN]

This are standard books for the examination. There can be other books but I am aware about this. I would also like you to suggest to go through online shopping website about books for the exam and read the review. By this way you will get more information about books available to study for the exam you are emphasizing upon.

I hope this answer helps you. All the very best for your future endeavors!