As you mentioned in the question, if you want it the way you showed in the screenshot:

Then you can try using the following CSS rules in Custom CSS section:
#sp-header {
height: 70px;
}
.sp-megamenu-parent > li > a {
word-break: break-word;
width: 95px;
line-height: unset;
padding: 0px 5px;
text-align: center;
vertical-align: middle;
}
Please go to Extensions -> Templates -> Styles and select your default template. Then go to Template Options and click on it. Then you can go to Custom Code and add this css code there.
After applying the CSS the site should look like this:
