Bedside tables are next to the bed, so I'm not sure what your question is. Can you give us more context?

Depends on ow much space you have on each size of the bed. If you have say 36 inches and then hit a door frame, then you need something smaller than 36 inches. We have a closet door and bathroom door on either size of our bed so the tables are small (I think 12-15" wide I'm not up there to measure exactly!) and they fit nicely with just a bit of space between bed/table and table/door frame.

Pictures would help!

I apologize for the lack of clarity.
This question is referring to a change order on a new build.

Context:
The distance between the bedside table windows on our drawings were designed for a guest room with a 7’ king size bed. We would like to change it to a queen size bed and the windows Will now have to be closer together. The drawings presently show only 2” on either side of the 7’ king size bed. But ours here at home has 8 inches on either side of our king size bed which I quite like. The 8 inches gives us 4-5” between the bedside table and the actual bed and another 3” on either side for the window to be centred over the bedside table and the window frame.

The question is:

How far apart should bedside table windows be from each other in the bedroom that has a queen size bed?

And why do bedside tables need to be centered under the window? Why do you need to change the windows? I'm confused. Sounds OCD to me!

We’re going from a 7’ king size bed down to a 5’ queen size bed in that room. The distance between the bedside table windows on the drawings were based on putting a 7’ king in that room.
The windows need to be closer together now. Question is, how much closer????

Well, if one bed is 5 feet wide and the other is 7, and you want the windows moved in accordingly, then move them in one foot on each side. 7 - 5 = 2, divided in half because of one on each side = one.

But the bigger question is how far apart are they planned now? I generally think that the windows in many houses are too close to the bed: window treatments and trim end up overlapped by the headboard, and things like that.

The drawings presently show 86” between the windows, Based on a king size bed.

Make sure you have a bit of a margin of wall for the Headboard, which will be wider than the mattress. Plus add the inches for the window trim. And if you are doing drapes or anything like that I would leave a bit of room for them so they aren't behind the headboard.

So I don't think 86" was enough for the King, maybe.

I would not move them in a foot, probably less.

Before you do this, how is this change going to look from the outside?

Precisely my train of thought. I measured ours at home and there is 8” on both sides of our king bed. It’s great to have those extra inches.

Kandrewspa, Good point. They’re framing it right now! It may be nudged to look better over basement window. Should have put a transom in there. More flexible.