"Load All" loads only from DB to Outlook, if you are not using LastModificationTime compare feature ( Assign Table-> Options-> Advnaced->Use LastModification to compare... )
If you are using this feature, the behavior depends on Conflict Resolution settings:
1.Ignore Item (no changes)
2.Outlook data will overrule the database data
3.Database data will overrule the Outlook data
4.Most recent time wins
Setting 2 will always update DB record when LastModificationTime differs.
Setting 4 will update DB record when Outlook LastModificationTime newer than DB LastModificationTime .