Here are the videos...
Photos from the clips:
Meeting at bottom of the stairs:
Dinner scene photos:
The main focus during the clips isn't the dialogue, it is about what Kate and Leo do during the 2 scenes. Eye-line match, gestures and finally their acting skills. Eye-line match means that the gaze of a character in one shot has to line up with the next shot with a different character. Examples of gestures are starring at each other, smiling, linking hands and laughing (all what Rose and Jack do).
Meeting at the bottom of the stairs clip. In this scene, When Rose walks down the stairs, Jack just stares at her and Rose stars back. When Jack kisses Rose's hand he said " I saw that in a nickelodeon one, and I always wanted to do it.". This makes laugh, Jack laughs as well. This is showing that Rose and Jack are comfortable with each other and this is when they start falling in love with each other. I really like the acting in this scene because Leo and Kate make it look really natural and also even though I have watched Titanic loads of times, this scene always makes me smile.
During the dinner table scene, you notice every once in a while you notice Rose and Jack exchanging looks and smiles. For example when Jack is talking about how great is life is and how he loves waking up in the morning not knowing what is going to happen or who is going to meet, Rose just stares at him. Rose smiles at Jack which causes Jack to smile too. I really like the acting in this clip because you are mainly focusing on the gestures and eye-line match between Leo and Kate.Also in this scene you can see Kathy Bates (Molly Brown) give Rose's mum (Ruth) the evil stare. The evil stare symbolises that Molly doesn't really like Ruth. She is a little bit up-herself and also she is suggesting to Jack she has more power than him as Jack is third class and Ruth is in first class, this is shown by Ruth saying "you find this sort of things appealing do you?".
When Jack says goodbye to everyone and then kisses Rose's hand again (just like the beginning of the night) and puts a note in her palm. They share glances at each other and when Jack leaves, Rose/Winslet looks down and smiles.
Script
I found the whole script for the film on a website and I found it very interesting to look at the script while playing the scene at the same time. At some bits, it is hard to follow but Jack still says the same lines.