Sets or gets the defining properties of the columns in a table.
Table columns do not store any data. They contain the
properties, such as the label and type, that define a table column.
Setting the columns property sets the columns
in the table.
Getting the columns property returns the current
list of columns in the table.
You cannot modify the data array in-place. To add, change, or remove individual columns:
columns property in a variable.columns property with the modified array.