The simplest way to solve your updating problem is to move the [Approve] column into Table 1. Then you would have access to it and the [Status] column together to change as needed.
However, assuming that there are other reasons you have [Approve] in Table 2, I would try resolving the problem with an Action attached the Form Saved behavior of your Table 2 Form.
This Action, call it Action1, would be of type “execute an Action on a set of rows”. In the Reference Rows property use a FILTER() expression for Table 1 where
[Key] = [_THISROW].[Ref Key]. The Referenced Action would Action2 described below.
Action2 operated on Table 1 and is of type “update some columns on this row”. This is where you set the [Status] column based on an expression. If [Approve] is “Approve” or “Reject”, then assign that value, else assign “New Job”. The expression might be like this:
IF(IN(LOOKUP(<value of approve from table 2>), LIST("Approve", "Reject")),
LOOKUP(<value of approve from table 2>),
Obviously, all of the details are not there. I’ll assume you know how to fill them in. If not, just ask.
Doing it this way you would not need a separate action/workflow when the value of [Approve] is set to “Pending”. The Action above will take care of it.