Web apps memory usage

I was asked for the memory usage of the web apps and it's like this currently:

  PID COMMAND      %CPU   TIME   #TH #PRTS #MREGS RPRVT  RSHRD  RSIZE  VSIZE
22993 chat 9005    1.2%  0:15.92   1    49   233  7.00M  6.77M  19.2M   215M 
22040 Map 9002     1.2% 17:48.79   1    49  3076   145M  3.27M  44.2M  2.99G
21175 simplebar    0.9% 11:56.19   1    49  1985  64.8M  3.75M  51.2M  1.93G
21174 simplePie    0.0%  7:05.87   1    49  1512   212M  3.53M   187M  1.62G
21169 PDF Test 9   0.0%  4:29.73   1    49  1432  43.0M  4.89M  48.7M  1.39G
21167 Infos 9001   1.1% 12:17.13   1    49  2636  69.5M  3.32M  30.3M  2.55G
21166 animated b   0.9% 20:36.78   1    49  2315   136M  3.75M  69.0M  2.39G

This is an 10 seconds average from top. And this is an older Mac Mini with 1.4 GHz. As you see the apps with pictures need more memory and if no session is running, the usage is hard to measure at all. Claris FileMaker Plugin