Possibly just an accidental error. Someone once used my card number to pay a mortgage isntalment over the phone. Obviously not deliberate as it naturally gave her name and address; somebody misheard or misread. Or it's even possible the credit card company has got it wrong on your statement
Alternatively, if someone has got hold of your PIN or something, the Just Eat food may just be a test before they make some bigger purchases. I'd call the card company asap and notify them. (They may need to cancel your card and issue a new one, depending what they find.)