unit price on table variant

You would have to add the line:
$price = $variant->prices[0]->price_value;

after the line:
foreach($element->variants as $k => $variant){

and change the line:
$html.='<td>'.$radio.'</td>';

to:
$html.='<td>'.$radio.round($price,2).' €</td>';

in the file administrator/components/com_hikashop/types/characteristic.php

Note that it would be better to do that modification as a characteristic display override:
www.hikashop.com/en/support/documentatio...tation.html#override
It's more complex but then you don't loose the changes when you update.