(noun): 食事/お食事ーmeal, 「お」is often added for politeness.
(verb): 食事するーto have a meal, to eat
「食」is associated with anything that is associated with FOOD. The moment you see it, you should know that we are talking about food.
It ranges from 食事（しょくじ）meaning meal, 食べる（たべる）- to eat, 食堂（しょくどう）- cafeteria, dining hall, 飲食（いんしょく）- drinks & food, to 断食（だんじき）- fasting.
Onyomi: ショク, ジキ in 食パン（しょくパン）- bread
Kunyomi: たべ・る,く・う, くら・う, は・む
「事」is has broader meanings associated with matter, thing, fact, reason, phenomenon, situation, affair, crisis, etc.
As 事（こと）, it denotes an individual phenomenon (as opposed to a general principle). But its essence changes according to the Kanji it gets clubbed with. For example, in 食事（しょくじ）it means something to eat, i.e a meal. But in 大事（だいじ）which means important, precious, it denotes a thing事 that matters to you a lot大. It also forms common words like 見事（みごと）meaning splendid, magnificent, superb, i.e something事 worth seeing見, 事故（じこ）meaning accident, and 物事（ものごと）which means a thing, something; everything.
Onyomi: ジ, ズ in 事故（じこ）accident
Kunyomi: こと, つか・う, つか・える
1. 油（あぶら）っぽい食事は好きじゃないです。I don’t like oily/fatty food.
2. 夜は家（いえ）で家族（かぞく）と一緒（いっしょ）に食事します。I have dinner with my family in the evening.
3. 明日、食事でもどうですか？I was wondering if you’d like to join me for a lunch/dinner tomorrow.
4. 本を読みながら食事をしてはいけません。Don’t eat while reading the book.