The contents of the Search Engine Keywords is used to block Internet search queries that would be considered inappropriate, based upon the words or phrases used in the search argument. This table of words and phrases is evaluated against each search query and when a match is made, the search query is blocked.
To enable this function of the Content Filter, you must check the option to 'Block Search Engine Keywords' through the General properties page of the Content Filtering Object. (more Help)
The list of keywords and phrases supporting this feature is totally distinct from the various category 'Keywords' that are used for categorizing unknown websites.
The Tools page includes a table-related database SEARCH utility and TOOLBOX utilities to assist with viewing and managing the contents of the table.
Search Engine Keywords Table - online Help
Blocked Search Queries Report - online Help