Personally, I like the table just about an inch below my elbows, when I'm standing next to it, which is 41-inches. My big router table which is made from a 6-8 X 3-6, solid core door is 36-inches high when I set it up. It is reserved for working on large flat pieces. Things like pattern routing plywood yard art.
Bill Hylton, the author of the two best selling books on the router ever published, has a design for one that is higher than that. He is over 6-ft tall, and for some operations prefers a table surface that is chest high.
If you haven't read his book on router tables, you probably should before you finalize your design.