Here's an SQL procedure for easily manipulating the table. You might need to clean up entries for the class/skill you're working with first, depending on what kind of changes you make.
Code:
DELIMITER $$
CREATE PROCEDURE setSkillCap(iskill int, iclass int, ibase int, imult int, istart int, istop int)
BEGIN
DECLARE i INT DEFAULT 1;
SET i = istart;
WHILE(i < istop) DO
INSERT INTO skill_caps VALUES (iskill, iclass, i, (ibase + (i*imult)));
SET i = i + 1;
END WHILE;
END$$
DELIMITER ;
Now if you want to let beastlords have double attack from level 30,
Code:
call setSkillCap(20, 15, 5, 5, 30, 71);