What this tantalum capacitor is rated for
The 1206 (3216 metric) case size is a common footprint, so it fits standard PCB layouts without a board spin.
What the ±20% tolerance means for your circuit
The ±20% tolerance is wide — actual capacitance can range from 26.4 µF to 39.6 µF. For a decoupling capacitor on a digital rail, that variation is usually fine. For a filter cutoff frequency or a timing circuit, the tolerance must be budgeted into the design margin. If your application requires tighter tolerance, a ±10% or ±5% tantalum from the same TAJ series would be a better fit.