You're begging to trip the breaker, yes, especially if your vacuum is a modern high-powered unit. Even a 20 amp circult is probably borderline.
If it were me, I'd move the halogen lamp, the computers and the fisk tank gear to a separate 15 amp circuit, and buy a small UPS (say 1000VA) for the computers and fish tank. Then you can plug the iron and vacuum into this circuit; if the breaker trips, your computers will run for a while from UPS, and if they're sleeping, your aquarium gear will keep running for a long time (probably hours). Handy if an electrical storm trips a breaker or GFCI while you're at work or sleeping.
Here's a tip... if you want to know what you're drawing, pick up a line conditioner that has a built-in ammeter. I have a few in my computer and music racks, my favorites (for value) are the ART PS 4x4. $99.99 from samash.com. 8 outlets, retractable rack lighting with dimmer and on/off switch, built-in 15A breaker and front-panel on/off switch, analog voltmeter (input) and ammeter on front. You can get much nicer ones (sequencing, etc.), but they cost more.
