looking something to clean mysql tables

[jet rex]

if on VB more 2000 users / min
too much mysql errors
a lots of people tell me to clean database
I want to clean at first table like

-rw-rw---- 1 mysql mysql 125M Jul 16 13:10 word.MYD
-rw-rw---- 1 mysql mysql 139M Jul 16 13:10 xperience_stats_changes.MYI
-rw-rw---- 1 mysql mysql 149M Jul 16 13:02 pmtext.MYD
-rw-rw---- 1 mysql mysql 169M Jul 16 13:10 xperience_stats_changes.MYD
-rw-rw---- 1 mysql mysql 174M Jul 16 13:10 postindex.MYD
-rw-rw---- 1 mysql mysql 210M Jul 16 13:10 postindex.MYI
-rw-rw---- 1 mysql mysql 300M Jul 6 19:50 postedithistory.MYD
-rw-rw---- 1 mysql mysql 492M Jul 16 13:11 postparsed.MYD
-rw-rw---- 1 mysql mysql 618M Jul 16 13:10 attachment.MYD
-rw-rw---- 1 mysql mysql 945M Jul 16 13:11 post.MYD