When you are having a meal with friends, you can say:

"Let's grab a bite to eat."
"Do you want to go out for a meal?"
"I'm thinking of getting together with some friends for dinner."
"I'm hungry. Do you want to meet up for lunch?"
"I'm organizing a dinner party at my place. Do you want to come?"

You can also use more casual phrases pke:

"Let's hit up a restaurant."
"Do you want to meet up for grub?"
"I'm in the mood for some takeout. Do you want to join me?"
"I'm thinking of ordering in. Do you want to sppt something?"
"I'm craving some good pizza. Do you want to join me for a spce?"