Use a coaster
Try not to leave anything damp or wet on a surface. If something is spilled on the table, wipe it up as quickly as you can until completely dry. Wet glasses and potted plants can leave unwanted watermarks on wood.
Don’t leave the table under the direct sunlight. If left out in the sun for long periods of time, the epoxy can fade, resulting in a loss of color from the table.
Water & Burn mark
At first, try using a small amount of olive oil on a cloth and rub it into the marked area. Typically this will take care of most minor issues. This article explains well on how to get rid of water and/or burn marks: https://lifeasmama.com/7-ways-to-remove-water-burn-marks-from-your-furniture/