If the data source is 1920KB in size then Tableau should have no problem with it in most cases - I've seen people use million+ row Excel data sources. In terms of why Tableau isn't working, the only situation I've run into with any regularity is that certain Compute Using settings and pill arrangements for table calculations can cause Tableau to attempt to perform so much densification that Tableau runs out of memory.
For us to help more, we'd need more details on the workbook and the problem you are experiencing.
Thanks again! Seems you are correct in terms of running out of memory. I tried a different format and it seems it can handle all the data. It appears if you ask Tableau to consolidate too much it stops working. All good. I found a work around. As usual, thanks!