Those are common problems and the good news is there are many easy solutions. Here are some free training videos from a professional trainer who is nationally recognized (Emily Larlham) all about teaching your dog to come when called:
Here is one that addresses jumping on tables:
And stealing food:
In general, it is important to remember that a 6mo puppy is still learning about the world and you need to employ a lot of management during this developmental period. Management includes tactics like putting the pup away when your child is eating, crating your pup when there's food on the table, clearing the table before giving your pup free roam, etc. You can also compromise in some ways. For example, if you want your dog near the family while eating, you can put a leash on her and step on her leash to prevent jumping. You can also give her a stuffed Kong or bone so that she has her own food project to work on while you eat your meal. This doesn't mean your dog is confined all the time, and it also doesn't mean you need to do this forever. If you are consistent about these practices for a few months, as your puppy goes through adolescence, she can have a lot more freedom when she matures - and you won't have to worry about unwanted behaviors.
Right now your puppy is going through development equivalent to kids going through the teenage stage. Biologically, your puppy's body is full of hormones that are changing her skeletal, muscular, and neurological systems as she reaches sexual maturity in a few months. Here's an analogy. Let's say you give a teenager your credit card, and on top of that you don't speak the same language so you can't tell the teen what she is allowed and not allowed to buy. You want the teenager to spend money on some things but not exceed a certain limit, or blow all the money on superflous things. But because the teen doesn't know what she's not allowed to do, she buys a bunch of clothes, games, food, jewelry... It gets out of control and you scold the kid every time she buys something that is not to your expectations. Yet you still have no way of telling her exactly how to use the credit card. This is basically like giving your puppy free roam of your house in all situations, and correcting her with a beep (or a shock, scolding, yanking, hitting, etc) when she does something you don't like. Sure, it might stop her in that moment. But the damage is done. If you scold your pup for jumping on the table, she has already jumped on the table and the habit gets a little stronger. Worse... like with teenagers and credit cards, and like with puppies that have too much freedom... If all you do is correct what you don't like, they just learn to do it when you aren't around to catch them. One pitfall that you probably don't want to fall into is the one where you constantly have to 'stay on top of' your puppy and correct her over and over again. It may feel like you are accomplishing something because the behavior you dislike stops when you intervene. But if you are repeating this over and over, day after day, the problem is not actually being solved.
The videos I linked you to, the advice of implementing management, and using positive reinforcement training, all help you proactively deal with these situations so that your puppy will learn to do exactly what you want her to do. And all this effort on the front end results in a dog you don't need to hyper manage in the future. I could leave a steak on the coffee table leave the room, and my dogs (one was ~70 lb and my current dog is 78) would not touch them.