Use sharp scissors
Make your bias tape on the diagonal. It lays down so much neater when ironing. I know sharp scissors sounded like a smart arse comment....lol I used to be an Upholsterer long ago, I have cut miles and miles of bias strips for use on furniture, automobile interiors etc. And having your scissors sharp makes for a cleaner edge.
Another option is a metal edge like this: This one is rather pricey but any aluminum straight piece of metal will work. Check the metal section at Home Depot they have some pieces around 48" which is perfect for use on a cutting table. With is method you can use a rotary blade.
https://www.cutting-mats.net/safety-...dges-2796.html