There should be a "browse" tab at thwe top of that page. You're simply viewing the table schematics on the initial page.
It's not your birthday anymore, so no more redundant answers 7 hours too late.
The width and height are showing up as 80 pixels for all profiles using stock avatars even though the stock avatars are not 80x80. How can I fix this?
It's probably something like this, which you can run under Control Panel » Database Tools » SQL Command. I'm no expert, so perhaps confirmation from someone else would be wise before doing this...:
update ubbt_USER_PROFILE set USER_AVATAR_WIDTH='48',USER_AVATAR_HEIGHT='48' where USER_AVATAR_WIDTH='80' and USER_AVATAR_HEIGHT='80'
Note: The above should change ALL 80x80 avatars to 48x48.