Each snapshot can grow up to its base disk's provisioned size, so it's not very surprising that disk space gets exhausted with multiple snapshots, and a lot of changes.
To find out what can/should be done, please provide some information. To get the required information, temporarily enable SSH on the host to allow putty and WinSCP to connect to it.
The VM's folder is "/vmfs/volumes/datastore1/vu18"
André