Definitely yes! SeekTable is suitable for embedding into multi-tenant web apps.
When values for (some) report parameters are passed in JWT payload that cannot be changed by the end-user in any way, so this could be 'organisation_id' and cube may use it to show only this tenant data. Actually, you can pass any 'context' you need and reports may be filtered for the particular user (or his role).
JWT token may be signed with a strong hashing algorithm like SHA256 or even SHA512. More than this, it may be encrypted with AES128 or AES256 so end user will not able to access values that are included into JWT payload.