Learning the English language and its vocabulary is important for academics and professionals, which is essential for effective communication. Reading books, newspapers, magazines, dictionaries, etc., can help to build a strong vocabulary and improve your communication. Listening to audiobooks and watching good English movies may also enhance the same. Speaking in English with friends and family members makes you master the language as well. Making a goal to learn some new words, phrases, or idioms daily boosts your vocabulary skills. Start with "A" alphabetically on day 1 and continue till the "Z" and again in rotation, this practice makes your vocabulary calibrated.
For a class 10th ICSE student, I would suggest the following list of books available on Amazon.
Word Power Made Easy, a complete handbook, published by W.R.Goyal: Norman Lewis, the American Grammarian, the author of this book presents an updated list of words to be learned quickly so that improved vocabulary guide, especially for high school learners.
Another masterpiece from Norman Lewis, 30 days to More Powerful Vocabulary, the book which is lightweight to be carried during travel, claims to strengthen your vocabulary skills in 30 days.
English Vocabulary in Use Elementary Book by Michael McCarthy and Felicity O'Dell (second edition) published by Cambridge contains vocabulary reference and practice along with answers. This has been definitely a good one for beginners in learning vocabulary and introduces easy ways to learn and remember new words.
Oxford Learners Pocket Word Skills by Ruth Gairns and Stuart Redman published by Oxford is pocket friendly in size that you can carry as a handy. Containing 32 modules with various topics, this book narrates vocabulary with pictures and is user-friendly too.
Last but not the least, Merriam-Webster's Vocabulary Builder is a complete guide for beginners as well as intermediate pupils. This book is a compilation of over 2300 words on different sections and teaches from the basics with quiz sessions after completing each section to check out your word power.