How to Add Parameters to Click Events
Background:
Method 1

Following the Fusion ProTable pattern, couple the action column directly with a Button component. Because the col.render function receives row data (record), the ProTable wrapper can pass col.render arguments through to the Button when rendering action column buttons.
Method 2
Slot + extended parameters

Set extended parameters to:
{
record: this.record,
index: this.index
}
Then the event handler receives them as the second argument:
onClick_new_new(...args){
console.log(args)
}