How do I Paint an old concrete patio table?

It’s painted concrete now?

In any case, I would first seal the porosity of the concrete with a exterior binding primer, after it is thoroughly cleaned. Fill the pores with the primer.

Then I would use a faux sponge roller cover and roll on a total of three similar exterior Grade paint colors, one at a time,

and hand wipe each color with a damp non-nap rag in the veining pattern I want. Rolled rag is another “faux” technic.

You may want to dilute the paint or glaze to make it more translucent.

Then clear coat with two full coats the completely dried paint job, high gloss exterior Grade polyurethane.

I would try marble contact paper like this one: https://amzn.to/2DkgD3T #affiliate