How to insert UNIQUE IDs values from several tables into events table
You can use this insert statement to insert some totally useless data in there (assuming the FK accuracy is not important here) but it satisfies your conditions.

    DELIMITER $$
DROP PROCEDURE IF EXISTS Events_insertion$$
CREATE PROCEDURE Events_insertion()
BEGIN
    DECLARE i  INT;
    DECLARE dTime DATETIME;
    SET i = 1;
    SET dTime = NOW();
    WHILE i  &lt;= 10000 DO
       INSERT INTO EVENTS_TEST VALUES
        (
        null,
        (ELT(0.5 + RAND() * 6, "rep_login",
            "rep_share",
            "email_viewed",
            "brand_page_opened",
            "media_viewed",
            "rep_contacted")),
        LAST_INSERT_ID()+2,
        LAST_INSERT_ID()+3,
        LAST_INSERT_ID()+4,
        LAST_INSERT_ID()+5,
        LAST_INSERT_ID()+6,
        (dTime + interval (LAST_INSERT_ID()) second),
        (dTime + interval (LAST_INSERT_ID()) minute)
        );
       SET  i = i + 1; 
    END WHILE;
END$$
DELIMITER ;


You can call this procedure like this

call Events_insertion();


and also try not to use name events as your table name since it is a reserved word.
Hope this could help you :)