Oilcloth is a special kind of fabric that is made by coating regular fabric with oil, which makes it waterproof and stain-resistant. It's like putting on a raincoat to stay dry in the rain, except it's a raincoat for fabric!
Oilcloth is often used to make things like tablecloths or aprons because it's easy to clean and doesn't soak up spills. You can just wipe it with a damp cloth and it will be good as new.
People have been using oilcloth for a long time, even back in the olden days when they didn't have fancy plastic tablecloths or waterproof jackets. They would use oilcloth to cover their tables or make raincoats for themselves.
Today, oilcloth comes in all sorts of fun colors and patterns, so you can find one that matches your style. And because it's so durable, it can last a long time, which is great for the environment because we won't have to throw it away and buy new ones all the time.