Nice tables! ??
I played around with it a bit more and I’m not sure if this is what you meant, but it may be closer to the look you’re wanting…
Instead of adding a logo, if you want a larger image, you could set it up more like a Header Image by setting a larger image as the background of the masthead (that whole space up top above your posts). I used Firebug to mock up an example of it on your site shown here: https://cloudup.com/cIHIo_nMICp.
To do that, add this CSS:
#masthead {
background-image: url("URL TO YOUR HEADER IMAGE");
background-repeat: no-repeat;
background-position: center;
background-color: #ffffff;
height: 160px;
}
.site-title, .site-description {
display: none;
}
For the header image I used in the example, I resized the height to 160px and set the height to 160px, so if you use a different size, make sure to adjust the number accordingly.
The image is small and not the full width of the space, so I set the background color as white, so that it fills in the space around the image. You can change that to whatever you want of course.
There are more adjustments that can be made to background images with CSS explained on this page: https://www.w3schools.com/css/css_background.asp
Let me know if you have any questions!