The white lines on your tomato leaves are the larva of a fly, commonly called as Leaf Miners.
Leaf Miner generally affects those plant which we eat and very difficult to control since they are in between the leaves layer.
How to solve this issue?
The first thing to do is to keep our plants safe from insects so that they can not lay eggs on the plants. If there are leaves already affected, we need to pluck those leaves from plants.
To prevent this from happening again using organic methods, we can spray Neem Oil around plants. Neem Oil acts as a repellent to insects and even stops larva from spreading.
Remember to use only organic neem oil here.
Learn about Neem Oil Here.
Can we eat Tomatoes from such plants?
Good News, Yes! Tomatoes are perfectly safe to consume.
Is there any other hack present over here?
Yes, We can plant some insect-repelling/attracting plants such as Marigold. However, results in such case will vary depending on many factors.
Always spray neem oil in diluted form and in the night or early morning to prevent leaves burn.