The .create table command is used to create a new table in a KQL database. The table schema must be defined within parentheses. Based on the sample data structure, Timestamp is a datetime type, and DeviceId is a string. The StreamData field contains a JSON object (a property bag with key-value pairs), which is correctly mapped to the dynamic data type in KQL. The other options are incorrect as .create function creates a function, not a table, and StreamData:long incorrectly types the JSON object as an integer.

Microsoft. (n.d.). .create table command. Microsoft Learn. Retrieved November 14, 2025, from https://learn.microsoft.com/en-us/azure/data-explorer/kusto/management/create-table-command

Reference: This document provides the official syntax for creating tables: .create table TableName ([columnName:columnType], ...) which directly supports the use of the .create table EventStreamData ( segment as the first step.

Microsoft. (n.d.). dynamic scalar data type. Microsoft Learn. Retrieved November 14, 2025, from https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/scalar-data-types/dynamic

Reference: This documentation specifies that the dynamic type is used to "hold arrays and property bags (dictionaries)," which corresponds to the nested JSON structure of the StreamData field in the sample data.