Ability to use smaller icons AND the ability to show the icons in a list format -- wonderful to stop navigating through the different Launchpad screens
This is a pretty old thread, but if it can be useful to someone. In fact, the option of using bigger or smaller icons already exists. Before you try it though, be aware that when you run the command in terminal, it resets your launchpad altogether. If your icons are already sorted in a particular order, know that you will need to reorganize them from scratch afterwards.
If you wish to go ahead and try it, open a terminal window and here are the commands. You can pick any number of rows and columns that best suits your need and your screen dimensions. There is a maximum superior value though, but I can't remember what it is precisely. Something around 25-30 rows or columns max.
defaults write com.apple.dock springboard-columns -int X;
defaults write com.apple.dock springboard-rows -int X;
defaults write com.apple.dock ResetLaunchPad -bool TRUE;killall Dock
You only have to replace the X variables by the number of columns and rows you wish to have respectively.
I personally use a 10 x 7 grid, so 70 icons per page for which you would write:
defaults write com.apple.dock springboard-columns -int 10;
defaults write com.apple.dock springboard-rows -int 7;
defaults write com.apple.dock ResetLaunchPad -bool TRUE;killall Dock
Depending on the computer model and in accordance with screen size and resolution, the number of rows and columns by default is not the same for all Macs. Make sure you take a note of what's the default on your Mac in case you ever want to revert the changes you've made. You use the same command in order to do that and replace the variables with the size of your original grid.
Hope that helps.