The model number of the carrier-locked version of the Galaxy Tab S10+ that appeared on Geekbench is SM-X828U.
The US variant of the Galaxy Tab S10+, as per the Geekbench listing, is powered by the MediaTek Dimensity 9300+ processor. This is MediaTek's most recent flagship chipset, launched a few months ago. It is fabricated on TSMC's 4nm (N4P) process node and features eight high-performance cores along with an ultra-powerful Immortalis-G720 MC12 GPU. This chipset is as powerful as the Snapdragon 8 Gen 3 in CPU and GPU performance.
Samsung has historically used two primary types of processors in its high-end tablets: its in-house Exynos chips and Qualcomm's Snapdragon chips. The use of MediaTek's Dimensity chips in the upcoming Galaxy Tab S10 would be a first for Samsung in its flagship-grade tablets or any mobile devices.