why not use min-column-width attribute where you can set the minimum column width for the table and you will get the scroller along x-axis which you can use to scroll through rest of the columns
<lightning-datatable
key-field="id"
data={data}
columns={columns}
min-column-width="100"
>
</lightning-datatable>
it will look something like this https://developer.salesforce.com/docs/component-library/tools/playground/6PhM9grWA/1/edit