I think it's normal, depending on how many time you want to get the position of devices, but also the number of devices you have, etc.
You can delete the content in tables, it depends on you, if you don't need to keep your old informations about devices positions, etc.
If you need them, maybe you should save them in an external support.
To delete content of a table in SQL, use TRUNCATE
https://sql.sh/cours/truncate-table
My traccar has 2 db eating up all server space as shown
Can I delete one or save some space by deleting some entries? If Yes how can I delete entries? I have cleared logs but I have all server space used up