If I recall the table seats 8 people. The table is oblong with the grill in the middle, 2 seats on each end and 4 across the front. I don't know how/where they would put 2 highchairs.
I ate there last year with my 2 year old. We put her high chair at the front corner of the table as it is furthest away from the grill. I suppose you could do this at each front corner?
Last year when I was there they put 9 adults at our table. If you are 8 adults/kids and 2 high chairs, you may all fit. Might be best to call and ask anyway.