Database Cleanup

Hi there,
I have a site that has a lot of entries in the wp_options table being autoloaded, my host has suggested I take a look as there should be no more than 800,000 and I have 1,176,570.

These are the top largest entries:

cf7_mch_471 69583
cf7_mch_8 67885
cf7_mch_3232 66844
cf7_mch_5275 65736
cf7_mch_4926 65505
cf7_mch_2666 65470
cf7_mch_1781 65338
cf7_mch_3306 65023
cf7_mch_3307 65023
cf7_mch_3308 65023
cf7_mch_961 64759
cf7_mch_2195 61354
cf7_mch_2198 61348
cf7_mch_2236 61348

I did some googling and it looks like these come from this plugin.

This is a total of 836,216. If I deleted these it would bring the total down to a good level. Is it ok to delete these?

Steve