Those are just side shoots and present no problem. My belief is that corn evolved them to act as decoys for insect pests. Some will produce a short tassel which can aid in pollination of the lower ears.

don't remove them, doing so will damage the plant

Anytime I have grown corn, least some of the plants have these.

Corn, like many of our grains, is just an over-excited grass.

Those "extra" stalks are called "tillers." The crown (or "main stem") of corn, just like other grasses, is actually very close to, or even under, the ground and the tillers ("stalks") are kind of like branches growing out of it. Having one single growth point, while great for human agriculture, would be pretty inefficient for the plant's survival and reproduction. Tillering is how they produce more leaves for photosynthesis and flowers for producing seed.

I believe some varieties, very old Indian corn varieties for example, are much more apt to produce tillers, and more of them, than newer ones which have been bred for ease of mechanical harvest. There may be some relationship to tillering and and environmental conditions as well, I'm not sure.

An interesting aside, tillers will eventually grow their own root systems and become completely independent of the "parent" plant, which is why its so easy to divide ornamental grasses and propagate them vegetatively.