The table contains all vesting shares (Hive Power) delegation operations from one account to another. The vesting shares are still owned by the original account, but content voting rights and resource credit are transferred to the receiving account.
Multiple operations involving the same accounts can be used to increase or decrease the amount of VESTS delegated.
If the amount is set to 0 then the delegation is removed. When a delegation is removed, the VESTS are placed in limbo for 7 days to prevent using them and voting on the same content twice.