Need a bit more information.
How much oil is the car consuming over mileage - i.e., car burns X number of quarts every X miles? Two quarts in roughly 10 days does sound fairly excessive - but how excessive depends on the miles driven and if you have any other issue, like oil leaks and whatnot. If you drove 2000 miles over that week and a half, that would put you at 1 quart every 1000 miles or so - not really good, but not terrible either, especially with a car with a lot of miles on the clock.
Also depends on the mileage you have on the engine, what transmission it has, and how it is driven. Also be nice to know the type of motor oil used, oil viscosity, interval between oil changes, etc. Oil changes done by yourself or quick lube places/dealership? This will be more important if you really do have a cam rattling issue.
The 1ZZ-FE engine is known to be very noisy at idle and at speed. See if you can pinpoint the noise more precisely - you mentioned higher RPMs, what kind of RPMs are we talking about - 3000RPMS, 4000RPMS, redline? Since this is a 2000 model year, they also introduced VVT-i to this engine - that has an associated oil control valve and oil control valve filter. If the car is running through a lot of oil, there is a good chance that the filter or control valve itself is clogged up. This will prevent the variable valve timing system from functioning properly - would cause some vibrations and rattles, due to the timing not being optimum for that particular load/RPM range.
1ZZ-FE is not really known for cam issue - but things that could be causing the rattling noise at speed - VVTi system being clogged, running too heavy of motor oil (starve the bearings in some cases), running with too little motor oil (again, starves bearings), bad oil pump, bad accessories, worn serpentine belt tensioner, or tired engine.
Some 8th gen Corollas had very high oil consumption - some on the order of a quart over hundreds of miles. Some are as bad as a quart every 100 miles or worse. Most are due to stuck piston rings, many are associated with 3-speed autos option on earlier 8th gen Corollas without VVTi (1998-1999 model years). Later models had some redesignes that seemed to help,m but some still had some excessive oil consumption. Sort of hit or miss - some have had no problems at all running hundreds of miles on their cars, some had problems from basically day one.