Bottom line up front: that trailer is too heavy.
I towed with my 2005 for 3 years. Started with a pup, then a hybrid TT, then a travel trailer. I weighed the rig a lot and spent a lot of time adjusting things so that I could almost stay within limits. My trailer is 33 ft, hitch weight is 750 lbs, total trailer weight is 6000 lbs. Those weights put me over on GCWR, at ther RAWR and slightly over on the truck's GVWR. I now have a 2008 Tundra, so I'm a little better off.
So, let's talk about your combo. First thing that leads to a big fat no way is thed hitch weight. The limit is 750 lbs with a WDH. The dry hitch weight on the Mallard is higher than that starting off and will only get higher. Don't exceed the 750 lbs limit, you could bend the hitch (I know this because I bent mine).
Next issue is the GVWR on your Tundra. You will exceed it with that trailer (especially with a cap). The key is will you exceed the RAWR. Maybe.
You'll be over on the GCWR but that doesn't bug me near as much as the hitch weight or the RAWR.
Based on the specs for the Mallard and my experience with Fleetwood and weights, that trailer will weigh at least 6500 lbs ready to camp (no liquids) and have a hitch weight north of 900 lbs. That is too much for a legacy Tundra. The new Tundra would fit nicely.
Sorry for the bad news. The good news is there are myriad lightweight offerings in that style that could easily be towed by your Tundra.
Trailer Details:
GVWR (lbs) 7,900
Cargo Carrying Capacity (lbs) 2,379
Gross Dry Weight (lbs) 5,521
Hitch Dry Weight (lbs) 801
DIMENSIONS AND CAPACITIES
Length (Feet and Inches) 29' 1"
Height (Feet and Inches) 10' 11"
Fresh Water Holding Tank (gal) 50
Grey Water Holding Tank (gal) 40
Second Grey Water Holding Tank (gal) 20
Black Water Holding Tank (gal) 40
Propane Capacity (lbs.) 60
Tire Size ST225/75 15D