Used in regression tests to test the created data table with a reference data table. The node will compare (depending on the dialog settings) the incoming tables during execute and fails with an exception if the tables are not equal (or do not meet the expectations). In that case the node stays not executed and the test will fail.
In the node's dialog, you can adjust how individual columns are compared. The default is to check for exact equality. For certain column types you can relax the comparison by using special checkers. Examples are numeric column where you may want to use an epsilon or string columns where you may want to ignore different line feed characters (Windows vs. Unix). The special checkers are used for the cell contents as well as for the column domain (i.e. possible values and bounds).
In case a column is a collection, you can select a checker for the elements' type which is then applied to every element in the collection (except the Equality checker which does look into the collection).
In order to configure column, change the checker in the second column and if applicable configure it in the panel below the column table.