I think i saw an option in game but still. Im french and right now a bit tipsy and i dont like reading really fast.
Any way to fix this? Even without the alcohol factor, would be better for me to at least have more time to read thoroughly.

You should be able to scroll back through the text. I believe there's a set of arrows on the left side of the text box for that purpose.

Yes you should be able to scroll. If there are no arrows try mousing over the text and see if the cursor turns into an up or down arrow. Then click. That's the way it works with Fallout 2.

Also, in case you miss something, at the bottom-left of the dialogue window there's a yellow and black REVIEW button. You can click that and it'll give you a recap of your conversation with that particular NPC.