I figured out a way to do this. In the exit event of each text-field, you can use the following:
for (i=0; i<Table1._Row1.count; i++) {
if (this.parent.index === i) {
this.resolveNode("Table2.Row1[" + i.toString() + "].Cell1").rawValue = this.resolveNode("$").rawValue;
}
}
just switch out Table2 for Table1 in the second table or repeatable subform