How could I modernize an antique coffee table?

Since it’s an antique, how much are you willing to change?

For example, refinishing it in another stained color, is minor.

Covering the top in glass mosaics is major.

It's an antique - does not have to match, just clean it good and put a glass top on it. If you want you can even put something under the glass, like photos. They can even be changed seasonally. Make it a focal piece in the room.

You could stain and put 3 coats of poly on the top, then stain the sides & bottom a different shade. That would keep in the spirit of the original finish.

If you want to completely change it, you could paint the entire piece of paint one part and stain the other. These could give it a more farmhouse vibe.

I would Formby's the top and paint the bottom to match the room. It already looks like two different woods were used for top and base/legs.

Here are some dining table ideas that you could use for your coffee table, if you want to paint it:

https://www.hometalk.com/diy/kitchen-dining/kitchen-dining-furniture/s-13-gorgeous-ways-to-bring-your-worn-kitchen-table-back-to-life-15366597

Chalk paint the legs a dark charcoal gray and stain the top a darker brown color. You can try General Finishes because there wouldn't be much prep work to redoing the top! Or if you want to sand it down to the wood there are some very pretty gray stains available. MinWax makes one. It really is a nice looking table! I would certainly keep it!

It looks to me like the top, especially where the cracking shows, is not level. This may present problems if you try to cover it with a new solid surface topping.

Before jumping in to this type of project, I would suggest that you check it out first with a large level.

"Antique", regarding furniture, means 100 or more years old. This looks like something 40-70 years old, that someone has already chopped the legs down to make it coffee table height. I've done this to several old dining tables that had no great monitary value. You don't mention your decorating style or that of the room, which would be helpful. Because the top is already distressed, I would go with a rustic or farmhouse vibe. People have already made good suggestions about painting the legs, and using chalk paint. I would do that in a color to coordinate with the room. I would screw reinforcing plates on the underside of the table, straddling the middle seem, to bring the two side level with each other. Then I would either Danish oil, or paste wax the top( if you like it a little rustic) or sand it smooth and then polyurethane it.