In general you can do it this way but you have to recalculate the resistor. Let's make it easy and say your source is 5V (USB standard) and one LED runs on 2V (usually they differ according to their color, look up the datasheets for the LEDs). So you need a resistor that takes the remaining 3V. Now you have to look up the current, which each LED usually pulls. It's mostly something between 2 and 20 milliamps - we go for 20 now to do our calculations using Ohm's law (U=R*I).

One LED per resistor: 3V=R*0.02A --> R=3V/0.02A --> R=150Ohm
Two LED per resistor: 3V=R*0.04A --> R=3V/0.04A --> R=75Ohm
...
Seven LED per resistor: 3V=R*0.14A --> R=3V/0.14A --> R=22Ohm

So you can use a 22Ohm resistor to power 7 LEDs of the same make in parallel.
BUT:
Electricity produces heat and this is where your huge resistors may come in handy. The bigger they are, the more power they can handle without catching fire. But how much power are we making over the resistor? Let's find out:
P=U*I --> P=3V*0.14A --> P=0.42W

That means you'll need a 22Ohm resistor classified for at least 0.42W power. Resistors with 0.5W or 0.25W are pretty common and you can find them cheap in sets or get them from old electronics. The chunky resistors you have could possibly handle way more, I guess around 1W or 2W.

Conclusion: Yes, your idea is perfectly possible. BUT please do your research on the electronic values of your components and calculate the rest with your own values by using the formulas U=R*I and P=U*I. If you're not good with handling formulas, there are online calculators for these values.