Quicken: When you cast a spell that has a casting time of 1 action, you can spend 2 sorcery points to change the casting time to 1 bonus action for this casting.
Eldritch Blast itself damages the target with beams. You get 2 beams at level 5, 3 beams at level 11, 4 beams at level 17.
Rotation
At level 8 you have 2 attacks for each Blast. On each attack the damage is 1d10 +4, for a total of 2d10+8. The attacks can be organized as follows:
Round 1: Hexblade Course + Blast for 2d10+14 (25 average) damage.
Round 2: Hex + Blast for 2d10 + 2d6 + 14 (32 average) damage.
Round 3 and 4: Quicken + 2 Blasts for 4d10 + 4d6 + 28 (64 average) damage.
At this point you will only have 1 sorcerer point and you cannot repeat the Quicken.
The rotation scales very well with levels. At level 11 you have 3 Beams per Blast and you have 8 sorcery points, meaning you have 6 turns of burst damage. At level 17 you will have 4 Beams per Blast, and 14 sorcery points. The damage becomes:
Round 1: Hexblade Course + Blast for 4d10+44 (66 average) damage.
Round 2: Hex + Blast for 4d10 + 4d6 + 44 (80 average) damage.
Round 3-9: Quicken + 2 Blasts for 8d10 + 8d6 + 88 (160 average) damage.
Rotation without sorcery points
When you run out of sorcery points or spell slots you can use Spiritual Weapon (assuming you still have Hexblade Course and Hex active).
Spiritual Weapon (bonus action): applies 1d8 damage every 2 slot levels.
The damage becomes:
Spiritual Weapon Lvl2 + Eldritch Blast (5 attacks total): 4d10 + 1d8 + 5d6 + 55 (99 average) damage
Spiritual Weapon Lvl4 + Eldritch Blast (6 attacks total): 4d10 + 2d8 + 6d6 + 66 damage
Making the damage reliable
In order to keep damaging the target you need to focus on a single one. Furthermore, because of the large number of attacks per turn, you NEED to increase your attack success rating, and you have several tools to achieve this result.
First of all, Faerie Fire gives advantage to you and your friends. Bless, Advantage and Elven Accuracy are very useful. Make sure to use Elven Accuracy whenever you have advantage, to increase the crit chance. Hexblade Curse allows you to crit with 19, which is a nice feature. You have other tricks in your spellbook, make sure to give them a look.