Changing your screen resolution will not affect the amount of white space showing when using percentages.  The tables using percentages will occupy the same relative amount of space on the screen while the tables using pixels while change.

To see the differences, compare the size of a pixel bar against the percent bar immediately above it.  Then change the resolution of your monitor and recompare the bars.  You should see that the percent bars have not changed in size.  The bars that are using a fixed pixel width will appear to have changed in size.

25% of screen

200 pixels

50% of screen

400 pixels

75% of screen

600 pixels

100% of screen

800 pixels