The RF 24-105mm f/4L and RF 24-240mm f/4-6.3 are similar weight... roughly 1.5 lb each, or about half the weight of the RF 100-500mm (which itself is a half lb. lighter than the EF 100-400mm II).
That 24-105L and 24-240mm are also pretty close in size, when fully retracted at the 24mm setting. The 24-240mm is about 1/2" longer, but slightly smaller diameter (72mm filters vs 77mm on the 24-105L).
The RF 24-105mm f/4-7.1 STM lens is the smallest and lightest at about 14 oz., as well as the smallest of bunch (at 24mm), about 1/2" shorter than the L version, and it uses 67mm filters. It's also a whole heck of a lot cheaper... close to 1/3 the price of the 24-105L. Also, this less expensive lens is actually able to produce higher magnification close-ups... 0.5X (compared to 0.24X with the L). That might mean no need for a separate macro lens (extension tubes can make either lens able to focus closer and at even higher magnifications).
However, if it were me, those were my only choices and my budget allowed I'd want the RF 24-105L for it's non variable aperture, better image quality at the wide end (
https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1222&Camera=1221&Sample=0&FLI=0&API=0&LensComp=1504&CameraComp=1221&SampleComp=0&FLIComp=0&APIComp=0), L-series build quality and sealing, and the fact that it can share 77mm filters with the RF 100-500mm. At the same time, there's minimal focal length overlap, the way there would be with the RF 24-240mm. Besides, a 1.5 lb. paired up with a 3 lb. lens still makes for a very light kit.
In fact, there are extensive reviews of all the available RF lenses at
https://www.the-digital-picture.com/Reviews/Canon-RF-Lens-Reviews.aspx" rel="nofollow" target="_blank">
https://www.the-digital-picture.com/Reviews/Canon-RF-Lens-Reviews.aspx. Brian's reviews are thorough and can be very helpful, along with the image quality, distortion, flare resistance, and vignetting tools he provides.
Maybe some day Canon will introduce an RF version of the EF 24-70mm f/4L IS USM lens. IMO that would be great... for my purposes, maybe even than the 24-105mm in some ways.
Right now, my personal "ideal" lens kit for an R-series camera includes:
RF 35mm f/1.8 IS STM Macro
RF 85mm f/2 IS STM Macro
RF 100-500mm f/4.5-7.1L IS USM
Either an RF 1.4X teleconverter or RF 800mm f/11
I would want a wider lens too, but not the rather big RF 15-35mm f/2.8L. I just don't need f/2.8 on this lens, so see no reason to spend a lot of extra $ for a bigger lens with it. There are rumors of RF 14-35mm f/4 and RF 10-24mm f/4 lenses in the near future (the latter might be a lens for an APS-C crop R-series camera, along with the RF 18-45mm lens that's also rumored). Right now an alternative might be the Rokinon/Samyang AF 14mm f/2.8, although I don't like that it can't use standard, screw-in filters. There are also some manual focus only ultrawides... 14 and 15mm. Those are possibilities too, since manual focus isn't too difficult with a wide lens thanks to great depth of field that's inherent to short focal lengths. Plus, for the types of subjects I typically shoot with ultrawides manual focus really wouldn't be a problem.