You can sorta cheat your way through this point using some tripmines.
The enemies come in three waves.
1) through the small door. This wave usually poses no problem.
2) Massive wave through the large open area, this is the wave that usually kills Lando. If they don't, they DO lure you back to the open area.
3) another wave through the door, if for some reason Lando survived, and heads his way into the Lady Luck. Since you are at the other end, it takes you awhile to get back, in the meantime this wave is blasting Lando inside the Lady Luck.
Here's what you do.
Drop some detonation packs outside in front of the first door (before you go into the area and Lando says "Hey buddy etc").
Then use five tripmines to block off the RIGHT side of the large open area (when you're facing it, ie the other side of where the shield and ammo generator are).
Put two tripmines up on the wall, on just near the edge of the open area, another one a few yards back.
Put three down on the floor facing up, so that they cannot pass into the open area without blowing themselves up.
When the first wave comes in, kill them as usual. Now, the second wave will try to spawn, but the first one that spawns sees all the tripmines and goes something like "Sh1tznaz! Wazzup wif @ll diz 733T wh0re m1n3sz?!!!!! "
He will then stay in place. Preventing the others from spawning. (sometimes the game realises this apparently before it sends in the second wave, and adds a few more guys to the first wave, but this varies). Lando, not seeing anybody, figures this is his chance, so he'll go into the Lady Luck.
Since YOU didn't have to run back to deal with the second group, you should also still be at the Lady Luck's entrance ramp, and you can follow Lando, then defend him against the third group (quite easy if you are already inside).
You have the detonator packs as a backup, I usually use them for the third group, but you can obviously use them against the first group as well.
This works like a charm in Jedi Knight and Jedi Master level, and I can't be arsed to keep reloading because Lando thinks he is some kind of 733T J3D1 and can run straight into ten bowcaster bolts...
Hope that helps.