On that page where you have that Table in Page Settings > Page CSS > Custom CSS area paste:
.sppb-addon-table thead > tr > th:nth-of-type(1) {width: 30%;}
.sppb-addon-table thead > tr > th:nth-of-type(2) {width: 30%;}
.sppb-addon-table thead > tr > th:nth-of-type(3) {width: 60%;}

In theory should work in Desktop view, if you have Header for Table :)
if not, try that:
.sppb-addon-table tbody > tr > th:nth-of-type(1) {width: 30%;}
.sppb-addon-table tbody > tr > th:nth-of-type(2) {width: 30%;}
.sppb-addon-table tbody > tr > th:nth-of-type(3) {width: 60%;}