How much heavier is a tile saw with a bigger blade?

Not necessarily. Blade diameter and rip length are different dimensions, and rip claims aren't compared here because fences and supports differ; the exact model's manual gives the tile sizes it handles. For large-format tile, QEP's 49 in bridge saw (83249) names it in its title.

As the makers' own figures, from 4 A on the 22400Q to 15 A on the D36000 and R4093. Neither says how cleanly a saw cuts, current isn't an electrical-suitability check, and the manual's circuit guidance for the exact saw still applies; weights may be counted with different included parts between makers.

QEP's 83249 page gives two different weights, one in its feature text and one in its dimension table, so neither is shown. Setting a weight limit removes it from the results. If you haul the saw to each job, three 7 in saws stay at 28.25 lb or less: the RIDGID R4021 and QEP's 22900Q and 700XT (22700Q).

Neither DEWALT page, for the D36000 or the D24000, gives a speed, and none is copied from another model. Where speeds are given they're each maker's maximum, from 3,400 RPM on the 83249 to 5,700 RPM on the R4031S.

RIDGID names a stand for the R4031S, R4041S and R4093. R4031S, in that common blade-size group, is listed at 45 lb and the R4021 tabletop at 27 lb, an 18 lb difference between models. The figures do not isolate the stand's weight. For the other seven, check the product page's box contents.