This is too much. If it's measured fine than your tables are exceptional. My Transactions table has 89 columns and the average record size is about 809 Bytes, and yours is 80 times mine Transactions table.

Can you please run this query in a new query of your database and share the results:

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED

select

cast(db_name(ps.database_id)+'.'+object_name(ps.object_id)+'.'+isnull(i.name,'heap') as varchar(60)) as db_table_index_name,

sum(ps.record_count) as sum_record_count,

avg(ps.max_record_size_in_bytes) as avg_record_size_in_bytes,

max(ps.max_record_size_in_bytes) as max_record_size_in_bytes

from sys.dm_db_index_physical_stats(db_id(), null, null, null, 'detailed') as ps --must DETAILED

left join sys.indexes as i on i.object_id = ps.object_id and i.index_id = ps.index_id

where object_name(ps.object_id) in ('Transactions')

group bydb_name(ps.database_id), object_name(ps.object_id), i.name

order bydb_name(ps.database_id), object_name(ps.object_id), i.name;