Hello
I completely understand the logic and I am writing a function as we "speak".
Your "From..until.." column is separated, based on ascending logic, in these areas: 1-30kgs, 30-100kgs, 100-600kgs, 600-1000kgs, 1000-2000kgs.
So what I do is find in which area the number is and round it up accordingly. Then by indexing your table I can calculate the Delivery Price.
Feel free to contact me for more details or any question you might have.
Thanks for reading,
Michael