For your model, you will want:

$2$ columns, one for each variable, in which you will type in the values of the variables for each feasible solution. Each row then is an alternative.

A column for each of the constraints. That column contains a formula to determine how much that alternative contributes toward that constraint.

A single column, with a single formula that indicates if that alternative is feasible.

A single column which uses a formula to determine the objective function value.

Above the top of the columns there should be a formula that identifies the maximum payoff.

Highlight the cells with the optimal solution and write a sentence telling the jewelry store what to do and what to expect.