@evleaks just posted today on twitter a picture of the upcoming Samsung Galaxy Tab S4 tablet white with the optional keyboard but with a S Pen:
TechRadar has two more colors: Black and Silver:
Samsung Galaxy Tab S4 S Pen with no clip.
dimensions of 249.3 x 164.3mm
2.3GHz octa-core chipset, which is likely the Snapdragon 835
GPU Qualcomm Adreno 540
10.5 inch display 1600 x 2560
64GB storage, micro SD support.
12MP rear camera, 7MP front camera.
LTE, Bluetooth 5.0, 802.11ac Wi-Fi.
Audio Tuned by AKG
The Samsung Galaxy Tab S4 is expected to be unveiled at IFA 2018 alongside the Gear S4 smartwatch in August 24.