Hi Ashley,
You can easily use your table, you can also go up to 72" table and seat 8 people. Having the kitchen open, if you need to sit more people you most likely can add an extension. Your buffet will fit also and if you getting a new table you can go a size wider.
As the light goes, you can go with a 26" diameter light it will be proportionate for that size room.
Q
I have the same shape dining room. Thank you for the input.
Q