There are theoretical limits (based on limitations of the operating system's ability to address memory) that you are highly unlikely to reach especially now that MATLAB is a 64-bit application.
There are also practical limits (based on how much memory is available on your system) that you likely won't reach.
2000 rows and 500 variables should be well within the practical limit unless you have a lot of other data in your workspace. You can check before filling in the data:
T = table('size', [2000 500], 'VariableTypes', repmat("double", 1, 500));