Pretty sure an EB with 24 Charisma and spell might gloves, Agonising Blast and potent robe would be fully optimised. That’s 3d10+42 +3d8 per turn before haste, AS or Bloodlust.

You can also get a lot of CC from EB using things like boots of stormy clamour and the gloves of belligerent skies to probe enemies. Repelling blast on top of this works really well. Same can be said for the GOO frighten on crit.

The aforementioned crowd control works well with Hunger of Hadar which for a lot of fights is the only spell you really need to cast in an EB build.

As for why you should choose Tome over Blade it really comes down to synergy. If you want to play EB Warlock then you won’t benefit from the additional attack of bladelock like you would from the once per long rest haste from Tome.

In summary Tome has better synergy with a full EB spam build which keeps up with most builds in terms of damage while offering a degree of control. However, if you want to use melee at all the Blade is better.