In this situation, you either have or have not had experience reading a high-pressure steam chart/table. If you have no idea what this is and have never used it, be honest with your answer. Otherwise, you can be brief with your answer in explaining what it is and why it is used. The interviewer is looking to determine whether you already have some basic field knowledge. If probed, you will want to give a specific example of using a steam table to gather information for the job you are working on.