Myths about open bar used by the mathematicians (6)
I believe the answer is:
'myths about open' is the definition.
I can't judge whether this defines the answer.
'bar used by the mathematicians' is the wordplay.
'bar' becomes 'table' (the bar is a counter or table in a pub).
'used by' says to put letters next to each other.
'the mathematicians' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'table'+'s'='TABLES'
Can you help me to learn more?
(Other definitions for tables that I've seen before include "Sets of data arranged in rows and columns" , "Lists of figures arranged in columns" , "Items of furniture" , "Turn these to upset the odds" , "Sets of facts and figures in columns and rows" .)