You can if you have an Androide cell phone. The App is called "tcallBlocking".  There is a free version in which you can block up to 3 ph. numbers and then a full version that costs $2.00, allowing you to block unlimited numbers.  I just bought the full version to use the wild card.  By using the wildcard, you can block an entire area code by entering <206*>.
I have been getting the same calls from various different "206" area code numbers, so I found this App and it has been working for me.