Each row is a room. Each column is a surface. The cells hold finish codes, and a legend or the spec explains each code.
Example: a painter reads the wall columns for every room and groups the rooms by paint type. A flooring estimator reads the floor and base columns.
Match each code to a spec section and a product. Check the remarks column, where designers put exceptions such as an accent wall. Compare the schedule to the finish plans if the set has both. If they disagree, ask before you price.