The numbers in the table seem way too low to me. For example, the table shows that you can retire with $20K of yearly income for 40 years with savings of $303K. That is a withdrawal rate of 6.6%. That equates to a substantial risk of running out of money in less than 40 years. The 4% SWR says you would need closer to $500K to be able to confidently withdraw $20K per year for 40 years.
Grumpy