How to apply an even coat to a coffee table when using oil based spray on polyurethane?

Is it spray on from a aerosol can? If so it is best to do more thin coats vs fewer thick coats. Also VERY important to shake can frequently. It's worked well for me.

When spraying a finish regardless if you are using rattle can finish or a sprayer you need to overlap each row of spray so it ends up having a uniform coat. Once you start you can't stop. If you stop or don't overlap each row it will leave a strip where the sheen is flat and or rough. Oil based is easier than some finishes as it dries slow. Some finishes like water based poly or lacquer dry so fast you have to lay it down pretty wet and really overlap it in order to get a uniform sheen.

It is a rattle can Minwax oil based polyurethane. We will sand the top of the coffee table lightly with extra fine steel wool and try spraying the table again. Thank you for all your help.

I would use sandpaper (or a Scotch Brite pad) versus steel wool. Steel wool can off metallic debris, that can interfere with a finish.

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Steel wool is alright for polishing but it wouldn't remove nibs and debris contained in the finish. Only sandpaper would be effective in smoothing the finish.