How do I change the icons in the right hand column? That is also tiny but virtually unaltered by the previous steps.

Open GIMP on your computer and go to the "Edit" menu in the top left corner. Select "Preferences" from the dropdown menu. In the "Preferences" window, click on the "Interface" category on the left side. Under the "Interface" category, you will see a section called "Icon Theme." Click on the arrow next to it to expand the section. In the "Icon Theme" section, you will see an option called "Icon size." This is where you can adjust the size of the icons in GIMP. Use the slider to increase or decrease the icon size. You can also manually enter a specific size in the text box next to the slider.