This is how I set my vise on the table, it open wide enough that it covers the table. My table is actually 9.5" wide for a bit of scale.
I was incorrect, I have 4" clear between the column and the table with almost 2" of overhang on the quill centerline. That is what happens when you pull up memories....
I looked closer at my parallels and they are indeed 6", I simply move them from side to side as required.
View attachment 507137