If I take my basic multivitamin with a full meal, is that better than taking it on an empty stomach?

Less side effects. Leaving aside whether there is any benefit for taking a multivitamin if you have a reasonably diverse diet, and reasonably normal gut, liver, kidney function, there is less chance of stomach upset, nausea, cramps, heartbirn, indigestion, etc. When taken with food. Vitamins are part of food after all. Difference in absorption not likely to be clinically relevant.