Welcome, Seleh. You have a very pretty spider plant! I believe those are aerial roots that we see growing
out of the base of your plant. I would just leave them alone to do what they do. Spider plants do have very heavy roots under there and become almost bulbous.
When I re-pot mine, there is usually very little soil left in the pot. It is all roots. I take them out of the gallon pots and set them on the ground. Then I take a flat shovel and cut away at least a third of the root on the bottom and an inch or two all around the sides. Re-pot with fresh soil in the same 1 gallon hanging pots on my porch. They respond very well to this treatment. Good tough plants.