Mahogany tables are sometimes built using the Sacred clay hammer obtained from the activity Stealing Creation; these double the amount of experience and save money. At current Grand Exchange prices, it costs 13,380 coins to build a Mahogany table. This is 15.93 coins/XP.
Mahogany tables are currently one of the fastest methods to train construction at a reasonable cost and efficiency rating. The tables yield around 450,000-600,000 experience per hour.