Table calculations are mainly for YTD, MTD reports and other table based calculations. The purpose of YTD, MTD reports to know numbers at the current date levels, such as - SUM of the Sales as of today starting from the first day of the month. Tableau Table calculations comes with inbuilt functions. The following are some of the different inbuilt functions in Tableau Table Calculations:
RUNNING_SUM for Running Summarized values on given column of a table.
RUNNING_AVG for Running Average values on given column of a table.
RUNNING_MIN for Running minimum values on given column of a table.
RUNNING_MAX for Running maximum values on given column of a table.
Some other table calculation functions include - RUNNING_COUNT, INDEX, FIRST, LAST, RANK and others.