A breakfast nook is a very vintage idea. This is especially true if you have an archway or if it’s in a seperate room instead of being part of the more modern open concept. However, since this classic style is so enduring you can really get this charming effect no matter what era your house was built in.
You’re going to need to go for a breakfast nook set. This could be a built in window seat or banquette. Otherwise look for series of benches that wrap around the corner of your room. Depending on the dimensions of your space you may have to just get them custom made. Typically this would just be in an oak wood. However, it does seem quite claustrophobic or even restaurant like in a small room.
Instead go for classic paint colors and fabric choices. This could be an elegant toile or even look for a patterned microsuede if you want something that’s going to be fairly easy to clean. This gives a more contemporary and updated look but it’s still vintage in style just because of the traditional furniture.