Broken tables

[Post title amended. You problem is no more urgent than anyone else’s.]

http://blog.pere24.ee/

Gave me raoprt that tables are broken. I did automatic table repair and got raport:

wp_usermeta: 1 client is using or hasn’t closed the table properly
wp_posts: 6 clients are using or haven’t closed the table properly
wp_comments: 15 clients are using or haven’t closed the table properly
wp_options: Table is marked as crashed
wp_postmeta: 7 clients are using or haven’t closed the table properly
wp_terms: 2 clients are using or haven’t closed the table properly
wp_term_taxonomy: 2 clients are using or haven’t closed the table properly
wp_term_relationships: 2 clients are using or haven’t closed the table properly
wp_commentmeta: 6 clients are using or haven’t closed the table properly

As there is 2 people with admin rights in this blog (and 15 authors with very limited access) then what this raport means? Right now blog came up but as much as I understand then this issue haven’t been fixed and it can crash soon again :/

What can cause this kind of issue and how to fix it correctly?

Thanks in advance!