cut the chair/table legs down,this will give the illusuion of the ceiling being higher.
Actually I would advise against this, I think if your furniture is too low the whole room will look "squashed down".
I also think using smaller than average-sized coving, as suggested by someone else, will make the height of the room look squashed. Coving in fact will give the illusion that your ceiling is higher, although that effect is mostly at the edges of a room and if yours is very large that effect might be lessened.
TBH I think the ceiling is probably looking low to you because the room is unfurnished, so when you look at the space the ceiling is acting as a false focal point. Once you have furniture in it your attention will be more drawn to the bottom (floor) half of the room and it won't seem so low-ceilinged. You say it is standard height so there's no reason to treat it as less than standard height.
I think if you use your furniture to define two seperate (dining / lounge) areas within the room, rather than each area being a through-way to the other area, then this will also visually break up the length of the room and will make it look less long-and-low.
You can do this and still keep the open-plan feel you planned: for example you can have a sofa with it's back to the dining area, with a console table or low bookcase behind it which will divide the space but without any barrier much higher than waist height, so you'll keep the open-plan feel.
Basically I think don't panic, it's an illusion, it'll all work out okay