These are RH tables for use with a psychrometer to take and track local weather patterns. I took the information from https://www.nwcg.gov/publications/pms437/weather/temp-rh-dp-tables and manually entered it into csv format.
How to use this table:
The top row of numbers moving right on the X axis are your wet bulb values. The Y numbers moving down on the left are your dry bulb values. Take your wet and dry values and find the intersecting rh.
ex: using RH table 0-500ft wet 23 dry 31 RH = 18