I'd buy a large tray and use the movable ottoman as a 'coffee table'

Get a couple C tables that you can move around as needed.

Hello LS-

A clearance for walking of 13" is pretty tight but very close to what I would call our "minimum coffee table clearance" of 14". Typically 18" is ideal and your coffee table should be 2/3 the length of the sofa run that it sits in front of. Depending on the users of this space it could work from a physical standpoint, but wiil be more diffcult for anybody that is very oversized or has any ambulatory issues. As far as the scale and how looks it it hard to say without photos. Good luck!

I agree with handy "C" tables that can move about, hold snacks and devices. Use the ottoman with a tray just for looks. Should be 12-18" from the sofa for navigation and to be reached easily.

I'd add a second matching ottoman. You can use it with a tray or a flat piece of the type of foamboard used for exercise flooring. Or move it up to the sectional for lounging options.

Those dimensions are wrong. I have this style sectional with almost the same size dimensions. I have a 3ftx3ft square table and it is a tight fit to walk around.

According to your dimensions of a 52" squared table with 13" on either side doesn't add up.

Unless you're saying the space in between is 78 in but the diagram is kind of misleading

Once you decide the proper size you might want to consider an item that is multipurpose.