I don't know as I blame you much

What does this sentence mean?
Does it mean I don’t blame you?
"I don’t know" means "I’m not sure"?
What does "as" mean in this sentence?

I’m sorry for the confusion.

It is from "Stuart Little – E. B. White".
The text is as follows：

"Ah," said Stuart, "summers are wonderful, aren’t they, Katharine?"

"Yes, and last summer was the most wonderful summer I have ever had in all my life."

"I can imagine," replied Stuart. "You’re sure you wouldn’t want to sell that little pillow?"

Katharine shook her head.

"Don’t know as I blame you," replied Stuart, quietly. "Summertime is important. It’s like a shaft of sunlight."