SVV_TABLE_INFO view shows information of all user-defined tables.Use the below query to determine the size of a table in Redshift database.
SELECT schema, "table", size "size in MB" FROM SVV_TABLE_INFO;
To sort the tables by size with largest table on top, use the order by clause as below:
SELECT schema, "table", size "size in MB" FROM SVV_TABLE_INFO order by 3 desc;