You don't have to make them laugh. If you put such pressure on yourself you will just end up feeling bad. Just try to contribute to the conversation around the table, whatever the subject is. If the topic is something you cannot relate to, try to learn more about it by asking relevant questions instead of just being a passive listener.
The placement around the table is quite important too, at least later in the evening. In the beginning it is more important to make a good impression to the whole group. As time passes you need to get closer to her. If you want to talk directly to her, it is best to sit in front of each other. However, there is some subconscious effect playing to your favor if she sits next to you, and you talk to the person on the other side of her, so that you have to lean over her. I don't know why, but I think the heat from your body and the unintentional kino (by sitting so close) trigger some circuits in her brain and make her more attracted. But at some occasion, you need to talk directly to her.
You can isolate her right at the table, you don't have to leave. But it depends on if the rest of the group will leave you alone or not. Keep strong eye contact all the time, it is important! (It has subconscious effects that you want to exploit). Make sure to have an interesting conversation with her, and make it last a long time. The longer the better. We are talking a couple of hours here. Also try to put some energy and passion into whatever you say. That will take her on the ride with the emotional rollercoaster. If there is a break, you need to regain her attention as soon as possible and continue. This will seduce her in time.
Good luck!