The only time we couldn't get seated was on Thanksgiving day. It opened at noon and we got there about 12:20. It was packed. The hostess said that there was a line of people waiting for it to open, and they filled up immediately at 12.
The 2-3 other times we've been there, seating was not a problem.
During the summer shade was a premium but we had no issue getting a table, just it was partially in the sun. If you want to guarantee a table just show up a few minutes before opening for a slightly early lunch and you will be all good.