Welcome to the Forum!! That is quite common with tomato leaves, usually the lower ones. Something gets at them, but the damage to the foliage is almost insignificant and has little or no effect on the fruit. Could be white flies? Like being a nervous Father-to-be! LOL. Normal! Throwing coffee grinds underneath can't hurt anything, and will eventually improve the soil. Wait for the "big ticket" concerns, and hope they do not confront you, like "Blossom Stem Rot" and "Tomato Blight"??
No, don't wait for either, just don't water from overhead, and relax and enjoy your efforts! Cheers!